One week of food: Part 1. Monday – Thursday.

Tell me what you eat, and I will tell you what you are.”

– Brillat-Savarin.

So said Jean Anthelme Brillat-Savarin, famed epicure and gastronome. What he would think of me from my food I do not know, perhaps lacking in the multiple courses and elegant French desserts of Brillat-Savarin’s own table. Being rather inept at remembering to keep a written diary I decided, out of interest, to keep a photographic record of everything I eat for one week. Whether this is of interest to anyone else I do not know. My diet is not set in stone, nor constant, and tends to evolve over time. Nor is it something I recommend for everyone or expect everyone to like as I eat the way I do for my own reasons. While it is difficult for the the observer not to alter what they are observing I shall attempt to eat as I usually do. So without further ado, on to breakfast.

This weeks food was to a large extent based on food cooked at the weekend, supplemented with some a few freshly cooked additions. As I am currently finishing up my PhD my time during the week is limited making cooking ahead more important. Particularly at busy and stressful times I find that eating nutritious and delicious food is important to maintain my health.

Monday

wp-1470688145600.jpg

Breakfast: 12 o’clock.

A late breakfast at work as I didn’t feel very hungry in the morning. Black coffee made in the cafetiere. The oxtail stew was made and the weekend and stockpiled in the fridge for the week. This consisted of a oxtail broth together with the meat of the bones, pot barley, parsnips, carrots, onion, kale, frozen peas, and dulse. While not always the most photogenic food, it is very satisfying, nutritious, and filling. The cherries are British grown and as they are currently in season, and delicious, I am making the most of them.

wp-1470688152714.jpgwp-1470688149528.jpg

Lunch: 4 pm

More of the same oxtail, pot barley, and vegetable stew.

wp-1470688127011.jpgwp-1470688133392.jpg

Dinner: 8 pm

Dinner consisted of a manx kipper (a whole smoked herring), a soft boiled local duck egg, with a mix of cooked kale, fresh broad beans, onion, and a tin of smoked oysters. The duck egg and vegetables had been cooked at the weekend and were reheated from the fridge. Plus a Hobgoblin Gold beer to finish.

Tuesday
wp-1470777551662.jpg

Breakfast: 8 am.

Duck eggs and whole grain rice, with kale, smoked mussels, fresh broad beans, and onion plus butter. All the food was cooked on sunday and reheated this morning. Plus a black coffee. As I had leftover food to use up this morning my breakfast was larger than it often is and I was feeling in need of something substantial. Even for breakfast plating food attractively is quite important to me even on a normal morning, I like my food to look nice.

wp-1470777568027.jpg

Lunch: 1 pm.

More oxtail, barley, and vegetable stew made at the weekend, cherries, and black coffee. I made the effort to actually go outside for lunch today as the weather was good for once, braving the seagulls that commonly patrol such areas of Aberdeen. Again premake food in the form of weekend stew makes for a substantial ready made lunch to take to work.

wp-1470777592693.jpg

Late afternoon snack: 5 pm. More oxtail stew.

wp-1470777598017.jpgwp-1470777606813.jpg

Dinner: 8pm.

Cold dinners are comparatively rare for me, as I live in a cold, damp northern climate hot dinners are rather more satisfying. But as it is summer and the weather is still closer to what would generally be called “warm” I am making the effort to with some good buffalo mozzarella and British grown tomatoes. Currently on my third can of a four-pack of Wychwood Hobgoblin Gold.

wp-1470777610401.jpg

Dessert: 9 pm.

The season for British cherries is to short not to be taken full advantage of. They also combine well with some Cornish clotted cream and heather honey.

Wednesday.

wp-1471174377487.jpg

Breakfast: 9 am

Steelcut oatmeal cooked in my pressure cooker with cherries, pecans, and honey.

wp-1471174396052.jpg

Dinner: 5 pm

An early dinner, as no lunch today, of oxtail, barley and vegetable stew and some beef cheek, butter bean and vegetable stew.

wp-1471380406469.jpgwp-1471380410526.jpg

Dessert: 9 pm

Strawberry cheesecake Häagen-Dazs and another beer.

Thursday

wp-1471380416328.jpg

Breakfast: 10 am

Beef cheek, butter bean, and vegetable stew.

wp-1471380420161.jpg

Afternoon snack: 2 pm

wp-1471380602411.jpgwp-1471380426327.jpg

Dinner: 9 pm

Oxtail, barley and vegetable stew and some beef cheek, butter bean and vegetable stew. Together with a scotch whisky.

 

For the rest of the week see the next post here>>>

Posted in Articles, Drink, Food, My week in food, Nutrition, Uncategorized | Tagged , , , , , | 1 Comment

Bone Broth, Gelatine, Oxalate, and Kidney Stones

Bone broth, also known as stock, is recently back in fashion with many purported health benefits. I will admit my own bias in being rather a fan of some good bone broth and suspect it is a beneficial component of the diet, although good research is currently still rather lacking.

However, it is important not to idolise particular foods, as almost all foods have some potential downsides. Therefore, I was interested to find a potential downside to bone broth in the link between broth, gelatine, oxalate, and kidney stones. This may seem unlikely as bone broth does not contain any oxalate, but bear with me as this first requires a diversion into the formation of kidney stones and where oxalate comes from.

Kidney stones

Kidney stones are really quite common, affecting about 1 in 10 people at some point in their lives. Most (~90%) kidney stones are formed of crystals of calcium and oxalate. Crystals of calcium oxalate begin to form when the concentration of calcium and oxalate reaches a high enough concentration. This means that a higher concentration of oxalate in the kidneys is a risk factor for developing kidney stones. As oxalic acid is found in a variety of foods, patients with recurrent kidney stones are often advised to limit their intake of foods containing a lot of oxalate. However, the oxalate from food only makes up a proportion of the oxalic acid in excreted from by the kidney, with estimates of between 24% and 53% originating from the diet (Holmes 2001).

Hydroxyproline metabolism

The rest of the oxalate passing through the kidneys is produced by the body itself. Oxalate is the final step in the breakdown of a common amino acid called hydroxyproline. Collagen is the major structural protein in the body and also the most abundant protein making up from 25% to 35% of all the protein in the body. Mostly found in fibrous tissues such as tendons, ligaments, and skin. It is also abundant in corneas, cartilage, bones, blood vessels, the gut, spinal discs, and the dentin in the teeth. Normally, the collagen in our connective tissues turns over at a very slow and controlled rate and is always slowly being broken down and rebuilt. This constant renewal of collagen requires the body to remove excess amino acids released during the process.

nihms-42105-f0005

The metabolic pathways of hydroxyproline metabolism into oxalate. Source: (Knight 2006).

The daily turnover of collagen from your own body is a major source of hydroxyproline. Just turning over your own collagen accounts for 5-20% of the urinary oxalate daily (Knight 2006). Excess hydroxyproline goes through a complex metabolic pathway in the liver. The majority of the hydroxyproline in this pathway is actually converted into another amino acid, glycine, and used for other purposes. There remainder is finally converted to oxalic acid and glycolate, which are excreted by the kidneys.

Bone broth gelatine contains hydroxyproline

Amino_Acid_Composition_in_Gelatin_chart

“Amino Acid Composition in Gelatine chart” by Hugahoody

We now return to bone broth of which hydrolysed collagen, better known as gelatine, is the main protein. It is gelatine that makes a good broth gel when cooled and contains the particular composition of amino acids that are currently making broth a popular health food. You can see from the pie chart below that hydroxyproline (Hyp) makes up 12% of the amino acids in gelatine. After eating broth or gelatine the body suddenly has a lot of hydroxyproline to deal with and a proportion of this is converted into oxalate.

A ten gram dose of gelatine increases hydroxyproline in the blood

nihms-42105-f0001

Change in blood hydroxyproline (Hyp) (inset), glycolate (■), and oxalate (–▲–) after ingestion of 10 g of gelatine. Source: (Knight 2006).

When gelatine is consumed there is a rise in the amount of hydroxyproline in the blood for several hours. In a fascinating paper from 2007, John Knight and his colleagues fed ten subjects thirty grams of supplemental gelatine and then measured their blood and urine. From their graph below you can see that the hydroxyproline (Hyp) levels rapidly rose in the blood and remained up to four times higher for several hours. However, oxalate levels in the blood are more tightly controlled and did not rise.

A ten gram dose of gelatine increases oxalate in the urine

nihms-42105-f0002

Amount of glycolate (■) and oxalate (–▲–)  in the urine following ingestion of 10 grams of gelatine. Source: (Knight 2006).

In comparison, the amount of oxalate in the urine increased for at least eight hours after consuming the gelatine. Oxalate concentration in the urine reached nearly five times higher a few hours after ingesting gelatine. This is due to the kidneys clearing oxalate out of the body as fast as it is being produced. This ten gram dose of gelatine would contain about a gram of hydroxyproline.

Lower doses of gelatine also increase oxalate in the urine

nihms-42105-f0004

Increases in urinary oxalate (■) and glycolate (□) excretion over fasting levels in a 6 hour period following ingestion of various amounts of gelatine. Source: (Knight 2006).

This is all very well you may say, but ten grams of gelatine is rather more than most people consume in one go. Well, the authors quite rightly followed this up with a range of doses of gelatine more commonly found in the diet. You can see from the graph below that one and two gram doses had little impact on the amount of hydroxyproline. Between five and ten grams of gelatine, there was a significant increase in both hydroxyproline in the blood and oxalate in the urine. Interestingly, 12 grams is the serving of gelatine recommended by a popular geleatine supplement company, just to give perspective on the amounts involved.

Relevance

It would be appropriate now to ask how relevant this information is. There is certainly no study on people who consume bone broth or gelatine regularly and their risk of kidney stones. There is some epidemiological evidence that suggests it may be relevant. This comes from studies comparing meat intake and vegetarians. A recent study has found an association between meat intake and kidney stones, with a significantly reduced risk of stones occurring in vegetarians or people eating less meat (Turney 2014). The hydroxyproline content of meat products is suspected to play a role in this increased risk. Meat is the main source of gelatine in most peoples’ diets and a hundred grams of beef can contain a few grams of collagen. Of course, this cannot be treated as conclusive evidence as it is only an association. In an older study, meat intake – which contains collagen and hydroxyproline – was linked to increasing oxalate excretion, but only in a subgroup of men with unexplained recurrent kidney stones (Nguyen 2001).

Implications

The research presented here is not a intended to scare people away from bone broth, stock, gelatine, or meat. Most people never get kidney stones and even for those who do, there are a number of factors that influence stone development. However, it is a potential factor that may be important for some people to know. As is it not commonly discussed, some people may not make a connection between broth or gelatine intake and kidney stones. If you need to reduce your oxalate levels, caution may be needed when taking extra gelatine or bone broth.

References
Holmes RP, Goodman HO, Assimos DG. (2001) Contribution of dietary oxalate to urinary oxalate excretion. Kidney International. 59(1):270-6.
http://www.ncbi.nlm.nih.gov/pubmed/11135080
“BACKGROUND: The amount of oxalate excreted in urine has a significant impact on calcium oxalate supersaturation and stone formation. Dietary oxalate is believed to make only a minor (10 to 20%) contribution to the amount of oxalate excreted in urine, but the validity of the experimental observations that support this conclusion can be questioned. An understanding of the actual contribution of dietary oxalate to urinary oxalate excretion is important, as it is potentially modifiable.
METHODS: We varied the amount of dietary oxalate consumed by a group of adult individuals using formula diets and controlled, solid-food diets with a known oxalate content, determined by a recently developed analytical procedure. Controlled solid-food diets were consumed containing 10, 50, and 250 mg of oxalate/2500 kcal, as well as formula diets containing 0 and 180 mg oxalate/2500 kcal. Changes in the content of oxalate and other ions were assessed in 24-hour urine collections.
RESULTS: Urinary oxalate excretion increased as dietary oxalate intake increased. With oxalate-containing diets, the mean contribution of dietary oxalate to urinary oxalate excretion ranged from 24.4 +/- 15.5% on the 10 mg/2500 kcal/day diet to 41.5 +/- 9.1% on the 250 mg/2500 kcal/day diet, much higher than previously estimated. When the calcium content of a diet containing 250 mg of oxalate was reduced from 1002 mg to 391 mg, urinary oxalate excretion increased by a mean of 28.2 +/- 4.8%, and the mean dietary contribution increased to 52.6 +/- 8.6%.
CONCLUSIONS: These results suggest that dietary oxalate makes a much greater contribution to urinary oxalate excretion than previously recognized, that dietary calcium influences the bioavailability of ingested oxalate, and that the absorption of dietary oxalate may be an important factor in calcium oxalate stone formation.”
Knight J, Jiang J, Assimos DG, and Holmes RP. (2006) Hydroxyproline ingestion and urinary oxalate and glycolate excretion Kidney International. 70(11): 1929–1934.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2268952/
“Endogenous synthesis of oxalate is an important contributor to calcium oxalate stone formation and renal impairment associated with primary hyperoxaluria. Although the principal precursor of oxalate is believed to be glyoxylate, pathways in humans resulting in glyoxylate synthesis are not well defined. Hydroxyproline, a component amino acid of collagen, is a potential glyoxylate precursor. We have investigated the contribution of dietary hydroxyproline derived from gelatin to urinary oxalate and glycolate excretion. Responses to the ingestion of 30 g of gelatin or whey protein were compared on controlled oxalate diets. The time course of metabolism of a 10 g gelatin load was determined as well as the response to varying gelatin loads. Urinary glycolate excretion was 5.3-fold higher on the gelatin diet compared to the whey diet and urinary oxalate excretion was 43% higher. Significant changes in plasma hydroxyproline and urinary oxalate and glycolate were observed with 5 and 10 g gelatin loads, but not 1 and 2 g loads. Extrapolation of these results to daily anticipated collagen turnover and hydroxyproline intake suggests that hydroxyproline metabolism contributes 20−50% of glycolate excreted in urine and 5−20% of urinary oxalate derived from endogenous synthesis. Our results also revealed that the kidney absorbs significant quantities of hydroxyproline and glycolate, and their metabolism to oxalate in this tissue warrants further consideration.”
Turney BW, Appleby PN, Reynard JM, Noble JG, Key TJ, Allen NE.(2014) Diet and risk of kidney stones in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC).European Journal of Epidemiology. 29(5):363-9.
http://www.ncbi.nlm.nih.gov/pubmed/24752465
“The lifetime prevalence of kidney stones is around 10 % and incidence rates are increasing. Diet may be an important determinant of kidney stone development. Our objective was to investigate the association between diet and kidney stone risk in a population with a wide range of diets. This association was examined among 51,336 participants in the Oxford arm of the European Prospective Investigation into Cancer and Nutrition using data from Hospital Episode Statistics in England and Scottish Morbidity Records. In the cohort, 303 participants attended hospital with a new kidney stone episode. Cox proportional hazards regression was performed to calculate hazard ratios (HR) and their 95 % confidence intervals (95 % CI). Compared to those with high intake of meat (>100 g/day), the HR estimates for moderate meat-eaters (50-99 g/day), low meat-eaters (<50 g/day), fish-eaters and vegetarians were 0.80 (95 % CI 0.57-1.11), 0.52 (95 % CI 0.35-0.8), 0.73 (95 % CI 0.48-1.11) and 0.69 (95 % CI 0.48-0.98), respectively. High intakes of fresh fruit, fibre from wholegrain cereals and magnesium were also associated with a lower risk of kidney stone formation. A high intake of zinc was associated with a higher risk. In conclusion, vegetarians have a lower risk of developing kidney stones compared with those who eat a high meat diet. This information may be important to advise the public about prevention of kidney stone formation.”
Nguyen QV, Kälin A, Drouve U, Casez JP, Jaeger P. (2001) Sensitivity to meat protein intake and hyperoxaluria in idiopathic calcium stone formers. Kidney International. 59(6):2273-81.
http://www.ncbi.nlm.nih.gov/pubmed/11380831
“BACKGROUND: High protein intake is an accepted risk factor for renal stone disease. Whether meat protein intake affects oxaluria, however, remains controversial in healthy subjects and in stone formers. This study was designed (1) to test the oxaluric response to a meat protein load in male recurrent idiopathic calcium stone formers (ICSFs) with and without mild metabolic hyperoxaluria (MMH and non-MMH, respectively), as well as in healthy controls, and (2) to seek for possible disturbed vitamin B(6) metabolism in MMH, in analogy with primary hyperoxaluria.
METHODS: Twelve MMH, 8 non-MMH, and 13 healthy males were studied after five days on a high meat protein diet (HPD; 700 gmeat/fish daily) following a run-in phase of five days on a moderate protein diet (MPD; 160 g meat/fish daily). In both diets, oxalate-rich nutrients were avoided, as well as sweeteners and vitamin C-containing medicines. Twenty-four-hour urinary excretion of oxalate was measured on the last day of each period, along with 4-pyridoxic acid (U(4PA)) and markers of protein intake, that is, urea, phosphate, uric acid, and sulfate. Serum pyridoxal 5′ phosphate (S(P5P)) was measured after protein loading.
RESULTS: Switching from MPD (0.97 +/- 0.18 g protein/kg/day) to HPD (2.26 +/- 0.38 g protein/kg/day) led to the expected rise in the urinary excretion rates of all markers of protein intake in all subjects. Concurrently, the mean urinary excretion of oxalate increased in ICSFs taken as a whole (+73 +/- 134 micromol/24 h, P = 0.024) as well as in the MMH subgroup (+100 +/- 144 micromol/24 h, P = 0.034) but not in controls (-17 +/- 63 micromol/24 h). In seven ICSFs (4 MMH and 3 non-MMH) but in none of the healthy controls (P = 0.016, chi square), an increment in oxaluria was observed and considered as significant based on the intra-assay coefficient of variation at our laboratory (8.5%). There was no difference in S(P5P)nd U(4PA)etween the groups after protein loading.
CONCLUSION: Approximately one third of ICSFs with or without so-called MMH are sensitive to meat protein in terms of oxalate excretion, as opposed to healthy subjects. Mechanisms underlying this sensitivity to meat protein remain to be elucidated and do not seem to involve vitamin B(6) deficiency.”
Posted in Articles, Food, Nutrition, Research, Uncategorized | Tagged , , , , , | 6 Comments

Victorian Flour Sourdough Bread

wpid-wp-1440248048869.jpg

Victorian flour sourdough bread – first attempt.

My previous experiments with sourdough bread sparked my interest in what other old varieties of wheat flour were available to try. Particularly those originating from, and grown in, the British Isles. It seems curious that while there has been a resurgence of interest in traditional varieties of many other food, wheat is still treated as an undefined commodity. The variety of wheat used to produce the flour is rarely mentioned, excepting the few ancient varieties of wheat like spelt of einkorn wheat that are still grown as specialty food crops.

Through searching online for heritage British wheat flour I found Bakery Bits, with an online store selling a variety of baking ingredients including a fascinating range of traditional flours from a guy called John Letts under the brand  Lammas Fayre.

“Lammas Fayre flour by John Letts at Heritage Harvest is a very special range of heritage and ancient English organic flours available online exclusively from BakeryBits.

The product of over a decade of sweat and academic rigour, John Letts has collected an extensive range of historically and botanically authentic cereals. All grown organically on farms in Buckinghamshire and Wiltshire, John grows them the traditional way, that is, in mixed populations (strains) that are well suited to local growing conditions.

Modern cereals are grown one strain at a time and for huge, uniform yields. These cereals need to be mollycoddled since they cannot cope with variable climates, pests or diseases. Growing mixed populations, the traditional way, ensures that there is always a reasonable crop – and the ancient cereals are adapted to seek the nutrients they need from unfertilised soil: the modern strains need to be pampered with lots of fertilisers.

The flour that John makes from these cereals are rare (no one else has them) and in many cases, once gone, they will be unavailable until the following harvest.

All the flours are excellent for artisan bread bakers and are perfect for those wanting to try something new (…or old).”

This resulted in my purchase of a range of the flours currently available.  The first one I tried baking with was the Victorian Blend White Flour.

“Lammas Fayre’s Victorian Blend white flour is milled from a mix of 19th century bread wheat (Triticum aestivum) varieties grown organically at Collings Hanger Farm in the village of Prestwood in Buckinghamshire, and at Sheepdrove Organic Farm in Wiltshire. Stoneground and roller milled flours are blended to create a delicious, light cream-coloured flour ideal for baking bread, cakes, scones and biscuits.”

This flour is smooth and very powdery to the touch due to the roller milling of some of the flour, a method that became common during the Victorian period. This time I decided to use some of the flour to make a sourdough starter of the same flour before baking, rather than using a rye starter, as I had previously done. My first attempt pictured above, produced an attractive but rather flat loaf, not helped by my forgetting about it and leaving it baking in the oven too long. The dough was rather runny, the same proportions as I used before seemed to contain too high a proportion of water. The second loaf I made with this flour reduced the amount of water added by 50 grams.

Recipe

For the sponge:

  • 150 grams of starter – made of equal weight of Victorian flour and water.
  • 250 grams of Victorian flour.
  • 225 grams of water.

For the dough:

  • 300 grams of Victorian flour.
  • 10 grams of fine sea salt.
  • 1 table spoon of olive oil.
  • 1 tablespoon of honey.

Otherwise the method of baking was the same as in my previous post. The addition of honey was on a whim, as I am generally rather a fan of honey, and it resulted in a very dark brown crust due to the added sugars.

The second loaf using this recipe produced a stiffer dough and a loaf that rose higher. It would have produced a better looking loaf it I’d scored the dough more deeply when putting it into the oven.

I’m looking forward to trying more of the heritage Lammas Fayre wheat flours.

wpid-wp-1440248033134.jpg

Victorian flour sourdough bread – second attempt.

 

Posted in Uncategorized | Leave a comment

Evidence of decreasing mineral density in wheat grain over the last 160 years

The wheat that we eat today has changed a great deal over the past century. The “Green Revolution“, the breeding of semi-dwarf, higher-yielding cultivars of wheat, and other cereal crops, has led to greatly increased grain production and crop yields since the mid-1960s. This undoubtedly contributed to the alleviation of global food shortages, however, modern plant breeding over the past sixty years has aimed for higher crop yields with little attention paid to the nutritional quality of the resulting cereal grains (Morris and Sands 2006). Increased yields of grain may have caused a reduction in the amounts of minerals in the grain, although this is difficult to test as the mineral contents can vary due to a wide range of factors including the plant variety, soil conditions, climate, and fertilizer treatment.

The Broadbalk Wheat Experiment

bottomcollageA study in 2008 aimed to limit these variable factors with the use of historic stored wheat samples from the Broadbalk Wheat Experiment. Started in 1843 and continuing to the present day this fascinating experiment has occupied 5 hectares of rural Hertfordshire, divided in the parallel plots, and tested different fertilizers and manure treatments on the most popularly grown wheat varieties of the day. All the while recording rainfall, temperatures, and storing away wheat and soil samples each year. In some of these plots, acting as controls, have varied little in their fertilizer treatments since the beginnings of the experiment.

Making use of these stored samples of grain, in their study in the Journal of Trace Elements in Medicine and Biology, Ming-Sheng Fan and her colleagues analysed the amounts of zinc, copper, iron, magnesium and phytate over the many years of the experiment.

Declining mineral content

Wheat minerals 1

Figure 1. Trends in wheat grain yield (a), harvest index (b), Zn (zinc) (c), Fe (iron) (d), Cu (copper) (e), and Mg (magnesium) (f) concentrations in wheat grain from three plots of the Broadbalk Experiment since 1845.

Beginning in the 1960s there is a clear trend for reductions in zinc, iron, copper, and magnesium. Between 1840 and 1960 the levels of these minerals had remained constant. This coincided with the increased yields due to the switch to new semi-dwarf wheat varieties. Between 1968–2005 in semi-dwarf cultivars, grain zinc, copper and magnesium concentrations decreased significantly in all plots. To quote the authors of the study,

“Mean concentrations in 2000–2005 were lower than the means of the long-straw cultivars by 33–49% for Zn, 25–39% for Cu and 20–27% for Mg. Grain Fe concentration did not show a significant decreasing trend during 1968–2005, but the mean concentrations were 23–27% lower than those of the 1845–1967 period. The trends of grain P, Mn, S and Ca (data not shown) were broadly similar to those of Zn, Cu and Mg…”

This could be due to the dilution effect, meaning that the grain is growing larger with the same mineral content, however the yields in Figure 1 suggest this is not the case. This shows that even in unfertilised wheat, where wheat yield did not increase, there was still the same drop in mineral content since the 1960s.

Direct direct comparison between the old and new cultivars

Between 1988 and 1990 in the  Broadbalk Experiment, an old tall variety of wheat called Squarehead’s Master was grown side-by-side with a modern semi-dwarf variety of wheat called Brimstone. This confirmed the previous trends as the Brimstone wheat had 18–29% lower concentrations of zinc, copper, iron and magnesium than Squarehead’s Master wheat.

Soil mineral concentrations

A common notion when discussing the nutrient content of modern food is that conventional farming causes a depletion of mineral nutrients in the soil, resulting in lower mineral concentrations in grain. To test for this the study authors measured stored soil samples from the past 160 years. Perhaps surprisingly they found that the concentrations of the minerals studied either remained the same or actually increased over the last 160 years. For sake of completeness they also measured the bioavailability of the minerals to the plants and found that the concentrations of bioavailable zinc, copper, and magnesium had all increased substantially over the last 160 years.

Phytate content of the wheat

The trends in the amount of phytate in the wheat was also measured as this is one of the best known modulators of mineral bioavailability in cereal grains. The ratio of phytate to minerals in the wheat declined over time.  This means there was more phytate relative to the amount of minerals and suggests that those minerals may be less well absorbed.

Conclusions

The declining mineral content of wheat reported in this study suggest that the Green Revolution of the 1960s has had an unintentional side effect decreasing mineral density in the wheat grain. This was due to the changes in the varieties of wheat grown, rather than farming practices, or use of extra fertiliser. The authors speculate one potential reason for this,

“Dwarfing of wheat cultivars is achieved by the introduction of the gibberellin-insensitive Rht genes [24]; as a result, proportionally more photosynthates are distributed to the grain. It is unlikely that the dwarfing genes would have a pleiotropic effect on the uptake of several mineral nutrients from the soil. A more plausible explanation is that the re-distribution of minerals from the vegetative tissues to grain does not catch up with the much enhanced re-distribution of photosynthates in the short-straw cultivars.”

Translated into English:

The reduced height (Rht) genes cause the wheat grow to a shorter height by making the wheat unresponsive to gibberellin, the equivalent of a plant growth hormone. Photosynthates are the sugars produced in the plant through photosynthesis, using energy from the sun. Growing shorter means less energy is needed for growth and more of those sugars are transported into the grain where they are formed into starch.

The authors speculate that the faster rate of sugars being transported in the grain and the resulting faster starch accumulating in the grain is not matched by an increase in minerals transported through the plant. So the overall density of minerals is reduced.

A limitation to this study was that only whole grain samples were analysed, as many people consume only refined white flour with much of the bran removed, where much the minerals are found. It would be interesting to know how much these decreases in mineral content has affected the minerals found in the starchy endosperm of the wheat, the part used to make white flour.

Still, even if you eat whole grain wheat products, due to the use of modern high-yielding wheat cultivars, you are unlikely to be consuming the same amounts of minerals as you would have done eating wheat 100 years ago.

References:

Fan MS et al (2008) Evidence of decreasing mineral density in wheat grain over the last 160 years. Journal of Trace Elements in Medicine and Biology. 2008;22(4):315-24
“Wheat is an important source of minerals such as iron, zinc, copper and magnesium in the UK diet. The dietary intake of these nutrients has fallen in recent years because of a combination of reduced energy requirements associated with sedentary lifestyles and changes in dietary patterns associated with lower micronutrient density in the diet. Recent publications using data from food composition tables indicate a downward trend in the mineral content of foods and it has been suggested that intensive farming practices may result in soil depletion of minerals. The aim of our study was to evaluate changes in the mineral concentration of wheat using a robust approach to establish whether trends are due to plant factors (e.g. cultivar, yield) or changes in soil nutrient concentration. The mineral concentration of archived wheat grain and soil samples from the Broadbalk Wheat Experiment (established in 1843 at Rothamsted, UK) was determined and trends over time examined in relation to cultivar, yield, and harvest index. The concentrations of zinc, iron, copper and magnesium remained stable between 1845 and the mid 1960s, but since then have decreased significantly, which coincided with the introduction of semi-dwarf, high-yielding cultivars. In comparison, the concentrations in soil have either increased or remained stable. Similarly decreasing trends were observed in different treatments receiving no fertilizers, inorganic fertilizers or organic manure. Multiple regression analysis showed that both increasing yield and harvest index were highly significant factors that explained the downward trend in grain mineral concentration.”
Morris CE. and Sands DC. (2006) The breeder’s dilemma – yield or nutrition? Nature Biotechnology. 24(9):1078–1080
“Plant breeders, challenged to create more nutritious crops, face seemingly radical choices that constitute a ‘breeder’s dilemma’. In the search for higher yields and lower farming costs, have breeders inadvertently selected for crops with reduced nutritional quality? To create foods that keep pace with our growing understanding of what constitutes healthy diets, plant breeders may need to make a significant shift away from traditional selection criteria. Subsidizing crop nutritional value rather than yield could be an important and economical driver for this shift in perspective.”

Posted in Articles, Food, Nutrition, Vitamins | Tagged , , , | 1 Comment

Minty Pea Purée on Sourdough Toast

wpid-wp-1438029304428.jpeg

Pea purée on buttered wholemeal spelt sourdough bread.

Few foods can match the vivid green of puréed frozen peas. The fresh taste of the peas combines beautifully with the mint an lemon to produce a very green flavour.

Gena Hamshaw of Food52 and creator of this recipe notes: “This dish is pure springtime comfort. A flavorful, bright green purée of mint, shallots, garlic, and peas meets crispy, rustic slices of toast.

Slices of toasted wholemeal spelt sourdough bread, lathered with a generous helping of butter, served as a fitting vehicle for these peas. The result was delicious and an excellent, sophisticated looking way of serving what is quite a simple meal of peas.

Ingredients (with slightly varying ingredients from the original recipe):

  • olive oil
  • A small red onion (instead of a shallot, thinly sliced
  • A generous helping of garlic, minced
  • An eyeballed quantity of frozen green peas
  • Some lemon juice
  • Salt, to taste
  • Black pepper, to taste
  • A handful of mint leaves
  • An onion was sliced and sauteed in olive oil for a couple of minutes. A generous helping of garlic and frozen peas was added and sautéed for another few minutes until the peas are warmed through.
  • The peas, onion, and garlic was placed in a food processor and the peas, lemon juice, lemon zest, salt, pepper , and mint leaves added in. The mixture was pulse mixed continuously until it is puréed but with some texture.Finally some extra mint leaves were blended in to taste.
Posted in Food, Recipes, Uncategorized | Tagged , , , , | Leave a comment

Adventures in sourdough bread.

wpid-img_20150721_102734.jpg

Wholemeal spelt sourdough bread with oxtail stew.

I have never baked my own bread. This is despite having had a go at cooking many different things over the years and so recently I decided to rectify this omission. Given that I have an interest in fermenting foods and historic cooking techniques the obvious choice was to attempt some sourdough bread with a fermentation of wild yeasts and bacteria.

This required both a starter and a method, as I had little knowledge on this subject. After searching around for recipes and becoming rather confused by the apparently many and various complicated methods for producing sourdough I stumbled upon an excellent article by Hugh Fearnley-Whittingstall in the Guardian newspaper. As usual Hugh manages to simplify the sometimes complicated subject of preparing  real food and make it readily understandable.

The first step was to make an active starter culture. I used Organic Wholemeal Rye Flour from Doves Farm to make the starter mixing together 100 grams of water and 100 grams of the flour in an open topped jar. The next day the same amount of flour and water were mixed in. Then each subsequent day the starter was halved and a fresh 100 grams of water and 100 grams of rye flour mixed in. The starter took a little while to get going but after a couple of weeks the culture was fermenting well and occasionally attempting to escape its jar.

Once my starter was ready it was time to move onto the bread baking. My sourdough making is complicated by the rather cool temperatures of my old granite Scottish home. With room temperatures rather lower than is normal my bread would require longer fermentation times than many recipes suggest.

Given my interest in the history of food and cooking I have so far chosen to try out a range of old varieties of wheat that I could get my hands on.

wpid-img_20150622_094044nopm.jpg.jpeg

Active wholemeal rye flour sourdough starter.

The recipe

For the sponge

  • 150ml active rye flour starter
  • 250g wholemeal spelt flour

For the loaf

  • 300g wholemeal spelt flour
  • 15 olive oil
  • 10g fine sea salt

Method

  • To cope with the cool temperatures, and the limitations of my being at work all day, I mixed the sponge in the evening after getting home from work.
  • The sponge was fermented overnight for 12 hours, by which time it had risen well and was frothy with bubbles.
  • In the morning I added in the salt, olive oil, and flour and mixed it into a dough. This was kneaded for 10 minutes and then placed in a greased bowl and covered in clingfilm.
  • After about 10 hours proving, when home from work, I punched down the dough and placed in a bowl lined with a well floured tea towel.
  • After about three hours proving again I heated the oven to 200C, sadly about he maximum my oven seems to reached judging my my oven thermometer, placing my cast iron bakestone in the oven preheat with a backing tray on the oven shelf below it.
  • The dough was turned out onto the hot bakestone and boiling water poured into the backing tray. The bread was baked for 40 minutes, topping up the boiling water at 15 minutes to maintain the humid atmosphere.

wpid-img_20150622_213425.jpgFirst sourdough bread – Spelt flour

This first loaf worked out really well and the spelt flour produced an earthy rich flavour when combined with the sourdough fermentation.

wpid-img_20150627_145708.jpg

Sourdough number two – Spelt flour.

This second loaf was also made with Doves Farm Organic Wholemeal Spelt Flour. Again the method worked well with spelt and scoring the dough when placing it in the oven helped the bread rise a little more than before.

wpid-img_20150704_192316.jpg

Sourdough number three – Einkorn flour.

Einkorn flour is the ancestor of all modern wheat, grown for many thousands of years since the beginnings of agriculture. The flour for this bread is Doves Farm Organic Einkorn Wholemeal Flour purchased from Real Foods in Edinburgh. Due to this it has a lower level of gluten than modern bread wheats, and the different structure of the gluten means it will never rise like a modern bread loaf. However, this current method I’m using produced a good loaf, equal in structure and shape to the spelt flour loaves. The flavour of einkorn in this bread is very distinctive, imparting a mild, almost nutty taste to the bread. This einkorn flour is also produced quite a pale light coloured loaf despite being wholemeal and the bran it contains much be light in colour.

wpid-img_20150715_234315.jpg

Sourdough number four – Khorasan (Kamut) flour.

For this loaf I used another ancient flour known as Khorasan, or Kamut, flour named after in the Khorasan region of Iran. This Doves Farm Organic Khorasan Wholemeal Flour was again found at Real Foods store in Edinburgh. Using the same method this flour produced a great tasting loaf, pale in colour and with a rich flavour all of its own.

wpid-img_20150721_102553.jpg

Sourdough number five – white spelt flour.

A new recent find in Aberdeen was some Doves Farm White Spelt Flour at the Grampian Health Food Store. This white flour had a lighter flavour due to the reduced bran, with a slightly more open texture to the bread.

This foray into bread baking has definitely stimulated my interest in the process of baking bread and sourdough fermentation. This method from Hugh Fearnley-Whittingstall has so far worked really well around the times I have available during the week and the cool temperatures in my home that require long proving times.

Posted in Articles, Food, Recipes, Uncategorized | Tagged , , , , , | 3 Comments

The origins of semi-dwarf wheat

Wheat

John Linnell, Wheat (1860)

The late summer landscape of 19th Century England, such as painted by John Linnell, was filled with fields of tall golden wheat ripening in the sun. Across the Atlantic the prairies of the midwest states inspired the words by Katharine Lee Bates to America the Beautiful,

O beautiful for halcyon skies,
For amber waves of grain,
For purple mountain majesties
Above the enameled plain!
America! America!
God shed His grace on thee,
Till souls wax fair as earth and air
And music-hearted sea!

In contrast today, on the prairies of the midwest or the fields of England, the wheat is unlikely to be so tall or waving in such a poetic manner. The wheat grown today is rather shorter and stockier, with stronger stems. This is a result of wheat breeding over the past hundred years to increase the yield of wheat by reducing plant height and make the plants resistant to lodging in conditions of intensive agriculture. Wheat breeders developed plants with shorter and stiffer straws, producing semi-dwarf, high-yielding varieties that were much better adapted to intensive agriculture. Before this time the traditional varieties of wheat grown were limited in the yield they could produce as adding more fertiliser resulted in the wheat stalks growing taller and weaker making them vulnerable to breaking.

The modern semi-dwarf varieties of wheat have recently come into public attention due to the publication of popular diet books blaming these new types of wheat for a plethora of modern health problems. However, rather than these alleged health issues, I was interested to know where these semi-dwarf wheats came from and the origin of the genes responsible. In an interesting article from 2005, Katarina and Ksenija Borojevic outline the history of the genes responsible for our modern dwarf wheat, with more of a focus on Europe, rather than the better known efforts in America that resulted in the Green Revolution.

The story starts further back than you might imagine, and to Korea, where naturally occurring short stemed wheat varieties were grown as far back as the third and fourth centuries A.D. The genes responsible were natural mutations rather than a production of any human intervention. These short varieties of wheat found there way to Japan as a result of the Korean-Japanese War during the sixteenth century. Semi-dwarf wheat varieties were widely grown in Japan by the 19th Century and served to provide the dwarfing genes for all our modern wheat varieties now grown around the world.

The variety Akakomugi, a 19th Century Japanese landrace of semi-dwarf wheat, provided the dwarfing genes first transferred to Europe in the early 20th Century. The Italian wheat breeder Nazareno Strampelli was to use this Japanese wheat, crossing Akakomugi with an Italian wheat by 1913 to produce a new shorter, lodging resistant Italians wheat. By 1918 a number of new semi-dwarf wheat varieties had been developed from this initial hybridisation which soon became very well known and were grown in Italy and South America, particularly in Argentina. By 1931 Nazareno Strampelli, using further hybridisations, had produced another improved variety called San Pastore that proved to be an extraordinary success and was widely grown in Italy and many other countries for more than 35 years.

These wheat breeding initiatives were supported and encouraged by the Italian government as they coincided with a drive for Italy to be self sufficient in food. This was known, as occurred during Mussolini’s time, as the Battle for Grain. These new semi-dwarf wheat hybrids enabled Italy to double its cereal production from 1922 to 1939 and and to become more or less self-sufficient in cereal production, where previously they had been heavily reliant on foreign imports.

After World War II, the Yugoslav government was also keen to encourage national self sufficiency and imported dwarf Italian wheat varieties during the 1950’s. These were widely grown, and through hybridisation with local wheats, enabled the development of new high-yielding winter wheat that were grown on a large-scale. Average yields increased from 1.36 tons of wheat per hectare up to 5.21 tones per hectare. Neighbouring countries including Hungary, Bulgaria, Romania, the former Czechoslovakia obtained similar results.

The gene responsible for reduced height originating in the Japanese Akakomugi wheat is known as Rht8 (abbreviated for reduced height 8). The function of this gene is still not clear but has been suggested to reduce sensitivity to brassinosteroids, a class of plant hormones that promote stem elongation and cell division. The identity of this Rht8 gene was only discovered at the end of the 20th Century and has been shown to have contributed its semi-dwarf characteristics of wheat across South Central Europe and the former USSR.

Semi-dwarf wheat reached the Americas via a completely separate route and through unrelated genes. Japanese wheat breeders, continuing their work on reduced height wheat, produced a new variety in 1932 that became known as Norin 10. This was produced by crossing an old Japanese dwarf landrace wheat called Daruma with American wheat varieties. Norin 10 grew to just two feet tall, instead of the usual four.

Norin 10 was never an important variety in Japan but found its way to the USA due to the occupying US army after the Second World War. S. D. Salmon, a scientist working on wheat research with the U.S. Department of Agriculture (USDA) was serving as an advisor of the occupation army when he made a  visit to the Marioka Agriculture Research Station on Honshu in Japan. He returned to the US, with wheat samples, given by Japanese scientists during his visit, Norin 10 was among these samples.  The genes making Norin 10 a short wheat  are the Rht1 and Rht2 genes that make the wheat plant insensitive to another type of plant growth hormones called gibberellins.

In 1952, an agronomist working at Washington State University called O. A.Vogel used this Norin 10 to cross with a popular wheat variety grown in Washington at the time. The resulting variety called Gaines became the predominant wheat variety in the Pacific Northwest in the late 1960s with farmers producing record wheat yields. It was from Washington State that Norin 10 was acquired by Norman Bourlag at the International Maize and Wheat Improvement Center (CIMMYT) in Mexico where new dwarf  wheat varieties were developed and later spread around the world, resulting in the Green Revolution and earning Norman Bourlag the 1970 Nobel Peace Prize. Adding the dwarfing genes in Norin 10 to their wheat breeding enabled the development of high yielding wheat varieties that could stand high levels of added fertiliser. These varieties developed at the CIMMYT dramatically increased wheat yields around the world, first enabling Mexico to become self sufficient in wheat and later countries like India and Pakistan.

It is clear the genes responsible for dwarfism in wheat plants have a long history and a complex route has taken them from ancient Korea into modern wheat plants in Europe and the rest of the world. While the work North America and the green revolution has attracted most of the attention, in Europe at least, genes introduced in the early 20th Century have also been important in the development of of modern wheat. It is also interesting that parts of Europe have been eating semi-dwarf hybrid wheat since the 1920s. Whatever the alleged health implications of these modern wheat varieties, the genes that make make them shorter have a long history and appeared spontaneously long before the work of modern genetics and crop manipulation.

 

Sources:

Borojevic K. and Borojevic K. (2005) The Transfer and History of “Reduced Height Genes” (Rht) in Wheat from Japan to Europe. Journal of Heredity96(4):455-459.

“Wheat is the main crop and often a strategic crop in many European countries. From a historical perspective, we describe the transfer of “reduced height genes” (Rht genes) from Japanese wheat varieties to wheat varieties in Europe and their influence on the increase of the total wheat production in the last century. Historic pathways of Rht genes were influenced directly or indirectly by wheat breeders exchanging seed samples and by some governments importing large quantities of wheat during historically critical periods for their countries.”

Borojevic K. and Borojevic K. (2005) Historic Role of the Wheat Variety Akakomugi in Southern and Central European Wheat Breeding Programs. Breeding Science. 55(3):253-256

“The old semidwarf, not very attractive, Japanese wheat variety Akakomugi was the source of the dwarfing gene Rht8 and photoperiodic insensitive gene PpD1 to many semidwarf wheat varieties in South and Central Europe in the 20th century. Integrating the Rht8 and PpD1genes in wheat varieties offered the best opportunities for reducing plant height, accelerating time of flowering, improving grain fill before the onset of dry summer conditions, enhancing spikelet fertility, and consequently increasing yields. Many breeders from South and Central Europe and from the former Soviet Union were creating winter short high yielding wheat varieties without knowing at the time that Akakomugi was the donor of such important genes. At the end of the 20th century, it was discovered that dwarfing gene Rht8 and photoperiodic insensitive gene PpD1 are located on the short arm of chromosome 2D in wheat. Microsatellite analyses proved that Akakomugi is the source for the Rht8 and PpD1 genes in many short wheat varieties in South and Central Europe.”

Posted in Articles, Food, Uncategorized | Leave a comment

Bourbon, Brandy and Armagnac: Phenolics and antioxidant capacity

In a recent post I looked into the science behind the phenolic compounds found in my favorite Scottish malt whiskies, and extracted into said water of life via the action of alcohol and water on the wood of the oak barrels they are aged within. I realise this was quite neglectful of the fact that a range of other distilled spirits undergo barrel aging to produce their unique characteristics. Thankfully science has not been so negligent on this topic and a study from 1999 in the Journal of Agricultural and Food Chemistry investigated this very subject.

spirits TAS

The graph shows the mean total antioxidant status (mmol/L) of distilled spirits analysed by Goldberg et al in their 1999 study.

This study analysed both the total antioxidant capacity and the amounts of a range of phenolic and furan compounds. This included both a single malt scotch whisky and a blended whisky, although unfortunately for comparison with my previous post they do not mention the age of this whisky. Judging from the amount of ellagic acid in the table below it could be suggested to be a 10-12 year old single malt. Of more interest here is that the study also included an American bourbon, French brandy and Armagnac. This study included a few different compounds found in barrel aged spirits. The structures of these are shown below, illustrating the complexity of compounds that develop during the aging process.

spirits TAS compounds

Structural formulas of the main compounds mentioned.

Looking at the graph above and table below a particularly interesting finding is that American bourbon exceeded the Scotch malt whisky in both its antioxidant capacity and levels of individual phenolic compounds. The authors suggest some reasons for this:

“Bourbon whiskey is made by rather different procedures. Two, in particular, are worthy of note. The distillation takes place at a quite low proof, not exceeding 160; this has the effect of allowing many congeners to pass over with the ethyl alcohol. The second is the use of charred oak barrels for aging, periods of up to 8 years not being uncommon. It appears that these two processes may account for the higher phenolic and furan contents and TAS of this whiskey compared with the previous three whiskies”

Perhaps also the use of freshly made oak barrels increases the transfer of phenolic compounds into bourbon, as compared to Scotch whisky which reuses previously used barrels. Vanillic Acid, Syringaldehyde were found in the highest amounts in bourbon. The lower levels identified in the Canadian rye whisky are mostly likely to a much shorter duration of barrel ageing.

spirits TAS table

The quantities of six polyphenols in the various spirits tested.

The striking feature of this study is the high amounts of all phenolic compounds in Armagnac, which had by far the highest concentrations of gallic acid, syringic acid, vanillin, and ellagic acid, as well as the second highest of vanillic acid, syringaldehyde, coniferaldehyde, and trimethoxyphenylacetic acid. This is possibly due to the exacting and protected methods used to produce Armagnac, of which wood aging of up to 10 years in Limousin oak for cognac and black Monlezun oak, a “black oak” from the Monlezun forest in Gascony, for armagnac, is a notable feature. Of interested, the ellagic acid found in both whiskies and Armagnac, is also proposed to be responsible for some of the health benefits of fruits such as blackberries, cranberries, pomegranates,raspberries, which are the main source of ellagic acid in the diet. However, the amounts in even Armagnac are rather low in comparison.

While the evidence from my previous post showed that long aged Scottish malt whisky, aged 25 years, had a much higher level of phenolic compounds than any in this study, the age of Scotch malt whisky at which most people drink it may not quite reach the levels of phenolics found in American bourbon, and is probably rather inferior to Armagnac. As the phenolic compounds extracted from oak wood during the aging of alcohol are common to all aged spirits, any health effects mentioned in my previous post would apply to all. However, it is worth remembering any possible health benefit is going to be redundant if consumed in large quantities.

*Any spelling mistakes in the post are due to the influence of good whisky.

References:

Goldberg DM, Hoffman B, Yang J, Soleas GJ. (1999) Phenolic constituents, furans, and total antioxidant status of distilled spirits. Journal of Agricultural and Food Chemistry. 47(10):3978-85

Abstract:

“The concentrations of 11 phenols and 5 furans were measured in 12 categories of distilled spirits by HPLC methodology, together with the total antioxidant status (TAS) of the same beverages. Ellagic acid was the phenol present in highest concentration in all beverages. Moderate amounts of syringaldehyde, syringic acid, and gallic acid, as well as lesser amounts of vanillin and vanillic acid, were measurable in most samples of whiskey, brandy, and rum but were largely undetectable in gin, vodka, liqueurs, and miscellaneous spirits. 5-(Hydroxymethyl)furfural was the predominant furan in the former three beverages, notably cognac, with 2-furaldehyde the next highest, but these were undetectable in most of the latter beverages. Highest TAS values were given by armagnac, cognac, and bourbon whiskey, all three of which tended toward the highest concentrations of phenols. Negative TAS values were exhibited by rum, vodka, gin, and miscellaneous spirits in line with the low or undetectable phenol concentrations in these beverages. Wood aging is the most likely source of phenols and furans in distilled spirits. Those beverages exposed to this treatment contain significant antioxidant activity, which is between the ranges for white and red wines, with the potential to augment the antiatherosclerotic functions attributable to the ethanol that they contain.

Posted in Articles, Drink, Nutrition, Uncategorized | 6 Comments

Oat Avenanthramides

Oats are one of the quintessential foods of the traditional Scottish diet. In terms of health benefits they are best known for their fibre content, particularly their beta-glucan content. Less well known is that this humble grain contains a unique class of more than twenty polyphenols known as avenanthramides, not found in any other foods. In recent years evidence has been emerging that these avenanthramides potentially have a wide range of beneficial effects on our health.

 

avenanthramides

 

Structure of avenanthramides

As well as being a staple food in Scotland and other regions of northern Europe, oats also have a long history in medicine. They have been used to treat various conditions such insomnia, anxietyand skin conditions, including eczema, and burns in various forms such as food, tea, or in baths. The use of wild oats (Avena sativa) has apparently been recorded for use in skin care as far back as 2000 BCE in Egypt and the Arabian peninsula and various skin conditions were often treated with oatmeal baths in the 19th and early 20th centuries. In 1989 the FDA recognised colloidal oatmeal as a safe and effective over the counter skin protectant drug and later in 2003 it was approved as an ingredient to be used as a skin protectant, one of the few botanical ingredients considered an effective skin protectant (Kurtz and Wallo 2007).

Until comparatively recently little thought had been given to the compounds in oats responsible for these anti-inflammatory activities of oats until the discoverly of avenanthramides in the late 1980’s (Collins 1989). These avenanthramides are a unique, group of soluble phenolic compounds which are not present in other cereal grains. These compounds are antipathogens (phytoalexins), meaning they are produced by the plant in to defend against plant pathogens such as fungi. While more than 20 different forms of avenanthramides are present in oats, three of these known as A, B, and C, make up the majority (Meydani 2009). These avenanthramides are now considered to form the active ingredients in oats responsible for their beneficial effects when applied to the skin.

Beyond the skin evidence is also emerging that these avenanthramides can have a range of beneficial effects within the body (Meydani 2009) . They have potent antioxidant properties potentially preventing the oxidation of cholesterol transporting low-density lipoproteins, at least in the lab (Chen 2004). Their anti-inflammatory effects may be able to help reduce inflammation in the cells lining our arteries (Liu 2004). Another interesting biological effect of avenanthramides is on nitric oxide (NO)-dependent vasodilation, a process that relaxes blood vessels leading to better circulation and reduced blood pressure (Nie 2006). Avenanthramides in very low concentrations have been shown to reduce inflammatory responses in skin cells and so mediate the anti-itch properties of oats when used on the skin, indicating that very little avenanthramides may be required to produce an effect (Sur 2008). Avenanthramides have been shown to be bioavailable in humans, being absorbed into the circulation, and to increase the antioxidant capacity of the blood in healthy older adults when fed enriched enriched oat products (Chen 2007). Even avenanthramides that are not absorbed could have an beneficial effects in our gut, given their anti-inflammatory effects when applied to the skin, this is speculative though.

Little information is currently available on the concentration of these avenanthramides present the oats used for our food, or the various oat products produced from them. One study that investigated the effects of processing on oats found that the avenanthramides content was much reduced in rolled oats, due to the effects of drum drying (Bryngelsson 2002). Rolled oats are steamed before being rolled flat, and require drying afterwards to remove the moisture added during the steaming process. The same study found that similar treatments to oatmeal, oats that had been heated and then then ground, had little on the avenanthramide content (Bryngelsson 2002). An earlier study found that the avenanthramides in products with added oatmeal such as bread, fresh pasta, muffins, and macaroni, survived well into the final products and end had an increase in free avenanthramides (Dimberg 2001). The amounts of avenanthramides can vary between different varieties of oats and survive storage and heating quite well (Dimberg 1996). A new method has even been proposed, using a process of “false malting” wherein selected or pre-treated grain is conventionally malted but does not germinate, that can dramatically increase the avenanthramide content of oats (Collins 2010). This suggests that the avenanthramides in the oats do survive into the food we eat, although there are still many unknowns about all the effects of oat varieties and processing techniques.

While little research has been carried out on the influence of avenanthramides in the amounts found in the oats we eat, they are an interesting group of compounds that potentially provide some extra benefits to eating oats and contribute to the healthfulness of oats as a part of the diet.

References:
Bryngelsson, S. et al. (2002) Effects of commercial processing on levels of antioxidants in oats (Avena sativa L.). Journal of Agricultural and Food Chemistry50:18901896.
“The effects of various commercial hydrothermal processes (steaming, autoclaving, and drum drying) on levels of selected oat antioxidants were investigated. Steaming and flaking of dehulled oat groats resulted in moderate losses of tocotrienols, caffeic acid, and the avenanthramide Bp (N-(4′-hydroxy)-(E)-cinnamoyl-5-hydroxy-anthranilic acid), while ferulic acid and vanillin increased. The tocopherols and the avenanthramides Bc (N-(3′,4′-dihydroxy-(E)-cinnamoyl-5-hydroxy-anthranilic acid) and Bf (N-(4′-hydroxy-3′-methoxy)-(E)-cinnamoyl-5-hydroxy-anthranilic acid) were not affected by steaming. Autoclaving of grains (including the hulls) caused increased levels of all tocopherols and tocotrienols analyzed except beta-tocotrienol, which was not affected. Vanillin and ferulic and p-coumaric acids also increased, whereas the avenanthramides decreased, and caffeic acid was almost completely eliminated. Drum drying of steamed rolled oats resulted in an almost complete loss of tocopherols and tocotrienols, as well as a large decrease in total cinnamic acids and avenanthramides. The same process applied to wholemeal made from groats from autoclaved grains resulted in less pronounced losses, especially for the avenanthramides which were not significantly affected.
Chen, CY. et al. (2004) Avenanthramides and phenolic acids from oats are bioavailable and act synergistically with vitamin C to enhance hamster and human LDL resistance to oxidationJournal of Nutrition. 134(6):1459-66
“The intake of phenolic acids and related polyphenolic compounds has been inversely associated with the risk of heart disease, but limited information is available about their bioavailability or mechanisms of action. Polyphenolics, principally avenanthramides, and simple phenolic acids in oat bran phenol-rich powder were dissolved in HCl:H(2)O:methanol (1:19:80) and characterized by HPLC with electrochemical detection. The bioavailability of these oat phenolics was examined in BioF1B hamsters. Hamsters were gavaged with saline containing 0.25 g oat bran phenol-rich powder (40 micromol phenolics), and blood was collected between 20 and 120 min. Peak plasma concentrations of avenanthramides A and B, p-coumaric, p-hydroxybenzoic, vanillic, ferulic, sinapic, and syringic acids appeared at 40 min. Although absorbed oat phenolics did not enhance ex vivo resistance of LDL to Cu(2+)-induced oxidation, in vitro addition of ascorbic acid synergistically extended the lag time of the 60-min sample from 137 to 216 min (P < or = 0.05), unmasking the bioactivity of the oat phenolics from the oral dose. The antioxidant capability of oat phenolics to protect human LDL against oxidation induced by 10 micromol/L Cu(2+) was also determined in vitro. Oat phenolics from 0.52 to 1.95 micromol/L increased the lag time to LDL oxidation in a dose-dependent manner (P < or = 0.0001). Combining the oat phenolics with 5 micromol/L ascorbic acid extended the lag time in a synergistic fashion (P < or = 0.005). Thus, oat phenolics, including avenanthramides, are bioavailable in hamsters and interact synergistically with vitamin C to protect LDL during oxidation.
Chen, CY. et al. (2007) Avenanthramides Are Bioavailable and Have Antioxidant Activity in Humans after Acute Consumption of an Enriched Mixture from Oats . The Journal of Nutrition137(6): 1375-1382
“The consumption of polyphenols is associated with a decreased risk of cardiovascular disease. Avenanthramides (AV), alkaloids occurring only in oats, may have anti-atherosclerotic activity, but there is no information concerning their bioavailability and bioactivity in humans. We characterized the pharmacokinetics and antioxidant action of avenanthramide A, B, and C in healthy older adults in a randomized, placebo-controlled, 3-way crossover trial with 1-wk washout periods. Six free-living subjects (3 mol/L, 3 F; 60.8 ± 3.6 y) consumed 360 mL skim milk alone (placebo) or containing 0.5 or 1 g avenanthramide-enriched mixture (AEM) extracted from oats. Plasma samples were collected over a 10-h period. Concentrations of AV-A, AV-B, and AV-C in the AEM were 154, 109, and 111 μmol/g, respectively. Maximum plasma concentrations of AV (free + conjugated) after consumption of 0.5 and 1 g AEM were 112.9 and 374.6 nmol/L for AV-A, 13.2 and 96.0 nmol/L for AV-B, and 41.4 and 89.0 nmol/L for AV-C, respectively. Times to reach the Cmax for both doses were 2.30, 1.75, and 2.15 h for AV-A, AV-B, and AV-C and half times for elimination were 1.75, 3.75, and 3.00 h, respectively. The elimination kinetics of plasma AV appeared to follow first-order kinetics. The bioavailability of AV-A was 4-fold larger than that of AV-B at the 0.5 g AEM dose. After consumption of 1 g AEM, plasma reduced glutathione was elevated by 21% at 15 min (P ≤ 0.005) and by 14% at 10 h (P ≤ 0.05). Thus, oat AV are bioavailable and increase antioxidant capacity in healthy older adults.”
Collins F. (1989) Oat phenolics: avenanthramides, novel substituted N-cinnamoylanthranilate alkaloids from oat groats and hulls. Journal of Agriculture and Food Chemistry37(1),:60–66
“Fractionation of methanolic extracts of oat groats and hulls by anion-exchange chromatography revealed the presence of a series of anionic, substituted cinnamic acid conjugates, trivially named avenanthramides. Two-dimensional thin-layer chromatography (TLC) showed groat extracts contain more than 25 distinct avenanthramides, while hull extracts contained about 20. Some 15 were common to both groat and hull preparations. The substances were purified by repeated column chromatography on Sephadex LH-20, using TLC to monitor purity, and crystallized from aqueous acetone. The complete structures of 10 avenanthramides have been elucidated using ‘H and 13C nuclear magnetic resonance (NMR), mass spectroscopy (MS), ultraviolet absorption spectroscopy (UV), and hydrolytic techniques and confirmed by total synthesis. The physicochemical properties, potential biological activity, and distribution within the oat grain are discussed.”
Collins, FW. (2010) Avenanthramides in oats: A new method of producing whole oats and oat ingredients with greatly elevated avenanthramide levels. Online. AACC International Cereal Science Knowledge Database.
“Avenanthramides, of which over 35 distinct components have been found to date, represent the major readily-bioavailable, soluble phenolics present in the oat kernel These hydroxycinnamoyl alkaloids are found only in oats and have been shown to not only act as antioxidants but also to inhibit the pro-inflammatory processes associated with atherosclerotic disease progression. Based on recent in vivo pharmacokinetic results in humans and in vitro human vascular cell culture models, effective concentrations of avenanthramides required to influence vascular antioxidant status and the inflammatory response can be provisionally projected. Threshold response levels (approximately 30 to 60 mg from a dietary source delivery system such as a 50 g serving of oat bran) would require an oat product with at least 600 to 1,200 ppm total avenanthramides. This is a significantly higher concentration range than those currently recorded for existing oat varieties or existing whole grain oat products. Recently a process has been found that significantly increases the levels of avenanthramides in native oat kernels. Levels ranging from about 900 to 2,000 ppm in the whole groat, representing an enrichment factor of about 25- to 40-fold have been achieved by this process, without significantly altering the milling quality of the product. The process involves the concept of “false malting” wherein selected or pre-treated grain is conventionally malted but does not germinate. The selected oats refer to “dormant oat” varieties, i.e. varieties exhibiting secondary dormancy and preferably hulless, while non-dormant varieties can be made dormant using a simple dry heat process. In-depth HPLC analyses of avenanthramides from oats treated by this patent-pending process show little if any qualitative differences relative to untreated oats. Abrasion bran fractions show levels as high as 3,500 ppm total avenanthramides.”
Dimberg, LH. et al. (1996) Variation in Oat Groats Due to Variety, Storage and Heat Treatment. I: Phenolic Compounds. Journal of Cereal Science. 24(3):263–272.
“Low molecular weight phenolic compounds present in heat processed oats (Avena sativaL) were analysed. The oat grains were of three varieties (Kapp, Mustang and Svea), stored at different relative humidities (30, 55 or 80%) and periods (3·5 or 15·5 months) and processed with or without hulls. Eleven UV-absorbing compounds detected by High Performance Liquid Chromatography were subjected to univariate and multivariate statistical analysis. The selected compounds included caffeic acid,p-coumaric acid, ferulic acid, vanillic acid,p-hydroxybenzaldehyde, vanillin, coniferyl alcohol, three avenanthramides and one unidentified substance. The levels of vanillic acid, vanillin and, especially,p-coumaric acid,p-hydroxybenzaldehyde and coniferyl alcohol increased significantly in samples processed with hulls, but not in samples processed without hulls. Ferulic acid increased in both processes, while caffeic acid and the avenanthramides were found to decrease during processing. Storage of unprocessed samples for 1 year generally increased the levels of phenolic acids and aldehydes. For the phenolic acids (except ferulic acid), this increase was most pronounced after storage at high relative humidity (80%). The avenanthramides were present at their highest levels in Mustang, caffeic acid in Svea and Mustang, the unidentified compound in Svea, while all the other compounds studied were present predominantly in the variety Kapp.”
Dimberg, LH. et al. (2001) Stability of Oat Avenanthramides. Cereal Chemistry. 78(3): 278-281
“The three main oat avenanthramides, N-(4′-hydroxy)-(E)-cinnamoyl-5-hydroxyanthranilic acid (Bp), N-(4′-hydroxy-3′-methoxy)-(E)-cinnamoyl-5-hydroxyanthranilic acid (Bf), and N-(3′,4′-dihydroxy)-(E)-cinnamoyl-5-hydroxyanthranilic acid (Bc), and their corresponding cinnamic acids, p-coumaric (P), ferulic (F), and caffeic (C), were investigated for stability to pH, temperature, and UV-light treatment. The retention of the avenanthramides after processing of oat-based food products was also analyzed. The avenanthramide Bc and the cinnamic acid Cwere sensitive to alkali and neutral conditions, especially in combination with heat treatment, whereas the other compounds studied were more stable. The cinnamic acids but not the avenanthramides were isomerized when irradiated with UV-light. The avenanthramides were restored after processing of oat-based products.”
Kurtz ES and Wallo W. (2007) Colloidal oatmeal: history, chemistry and clinical properties. Journal of Durgs in Dermatology. 6(2):167-70.
“Oatmeal has been used for centuries as a soothing agent to relieve itch and irritation associated with various xerotic dermatoses. In 1945, a ready to use colloidal oatmeal, produced by finely grinding the oat and boiling it to extract the colloidal material, became available. Today, colloidal oatmeal is available in various dosage forms from powders for the bath to shampoos, shaving gels, and moisturizing creams. Currently, the use of colloidal oatmeal as a skin protectant is regulated by the U.S. Food and Drug Administration (FDA) according to the Over-The-Counter Final Monograph for Skin Protectant Drug Products issued in June 2003. Its preparation is also standardized by the United States Pharmacopeia. The many clinical properties of colloidal oatmeal derive from its chemical polymorphism. The high concentration in starches and beta-glucan is responsible for the protective and water-holding functions of oat. The presence of different types of phenols confers antioxidant and anti-inflammatory activity. Some of the oat phenols are also strong ultraviolet absorbers. The cleansing activity of oat is mostly due to saponins. Its many functional properties make colloidal oatmeal a cleanser, moisturizer, buffer, as well as a soothing and protective anti-inflammatory agent.”
Meydani M. (2009) Potential health benefits of avenanthramides of oats. Nutrition Reviews. 67(12):731-5
“Oats are known to be a healthy food for the heart due mainly to their high β-glucan content. In addition, they contain more than 20 unique polyphenols, avenanthramides, which have shown strong antioxidant activity in vitro and in vivo. The polyphenols of oats have also recently been shown to exhibit anti-inflammatory, antiproliferative, and anti-itching activity, which may provide additional protection against coronary heart disease, colon cancer, and skin irritation.
Nie L. et al (2006) Avenanthramide, a polyphenol from oats, inhibits vascular smooth muscle cell proliferation and enhances nitric oxide production. Atherosclerosis186:260266.
“The proliferation of vascular smooth muscle cells (SMC) and impaired nitric oxide (NO) production are both crucial pathophysiological processes in the initiation and development of atherosclerosis. Epidemiological data have indicated that diets rich in whole grain foods are associated with a reduced risk of developing atherosclerosis. Avenanthramides are polyphenols found exclusively in oats (Avena sativa L.). The present study was conducted to examine the effect of synthetically prepared avenanthramide-2c on the proliferation of SMC and NO production by SMC and human aortic endothelial cells (HAEC). Avenanthramide-2c significantly inhibited serum-induced SMC proliferation. At a concentration of 120 microM, avenanthramide-2c inhibited more than 50% of SMC proliferation, as measured by [3H] thymidine incorporation, and increased the doubling time of rat SMC line (A10) from 28 to 48 h. Treatment of human SMC with 40, 80, and 120 microM avenanthramide-2cinhibited cell number increase by 41, 62, and 73%, respectively. In addition, avenanthramide-2c treatment significantly and dose-dependently increased NO production in both SMC and HAEC. At a concentration of 120 microM, avenanthramide-2c increased NO production by three-fold in SMC, and by nine-fold in HAEC. These increases were in parallel with the up-regulation of mRNA expression for endothelial NO synthase (eNOS) in both vascular SMC and HAEC. These results suggest that the avenanthramides of oats may contribute to the prevention of atherosclerosis through inhibition of SMC proliferation and increasing NO production.
Sur R. et al. (2008) Avenanthramides, polyphenols from oats, exhibit anti-inflammatory and anti-itch activity. Archives of Dermatological Research300:569574
“Oatmeal has been used for centuries as a soothing agent to relieve itch and irritation associated with various xerotic dermatoses; however few studies have sought to identify the active phytochemical(s) in oat that mediate this anti-inflammatory activity. Avenanthramides are phenolic compounds present in oats at approximately 300 parts per million (ppm) and have been reported to exhibit anti-oxidant activity in various cell-types. In the current study we investigated whether these compounds exert anti-inflammatory activity in the skin. We found that avenanthramides at concentrations as low as 1 parts per billion inhibited the degradation of inhibitor of nuclear factor kappa B-alpha (IkappaB-alpha) in keratinocytes which correlated with decreased phosphorylation of p65 subunit of nuclear factor kappa B (NF-kappaB). Furthermore, cells treated with avenanthramides showed a significant inhibition of tumor necrosis factor-alpha (TNF-alpha) induced NF-kappaB luciferase activity and subsequent reduction of interleukin-8 (IL-8) release. Additionally, topical application of 1-3 ppm avenanthramides mitigated inflammation in murine models of contact hypersensitivity and neurogenic inflammation and reduced pruritogen-induced scratching in a murine itch model. Taken together these results demonstrate that avenanthramides are potent anti-inflammatory agents that appear to mediate the anti-irritant effects of oats.
Liu L. et al. (2004) The antiatherogenic potential of oat phenolic compoundsAtherosclerosis. 175(1):39-49
“Avenanthramides are phenolic antioxidants, which are present in oats. Avenanthramides A, B, and C are the major constituents of the total soluble antioxidant phenolic compounds in oats. We tested the potential antiatherogenic activity of partially purified avenanthramides from oats by examining their effects on adhesion of monocytes to human aortic endothelial cell (HAEC) monolayers, expression of adhesion molecules, and production of proinflammatory cytokines and chemokines by HAEC. The oat avenanthramides mixture was prepared and partially purified by column chromatography. This avenanthramide-enriched mixture (AEM) had no toxicity to HAEC as tested up to 40 ng/ml. The pre-incubation of HAEC with 4, 20, and 40ng/ml AEM for 24h significantly decreased adhesion of U937 monocytic cells to interleukin (IL)-1beta-stimulated HAEC in a concentration-dependent manner. Pre-incubation of HAEC with AEM at 20 and 40 microg/ml, but not at 4 microg/ml, for 24h significantly suppressed IL-1beta-stimulated expressions of intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin and the secretion of proinflammatory cytokines IL-6, chemokines IL-8 and monocyte chemoattractant protein (MCP)-1. These data provide evidence for the potential anti-inflammatory and antiatherogenic effects of antioxidant avenanthramides present in oats.
Posted in Articles, Food, Nutrition, Uncategorized | 3 Comments

Whisky polyphenols and their potential health effects

IMG_20150315_180954

Scapa, one of my current Scottish whiskies

Scottish malt whisky, unlike other beverages such as red wine, tea or coffee, has received little attention with regards to its phenolic plant phytochemicals.

In the production of malt whisky the pure distilled spirit is aged in oak barrels for a number of years. During this aging constituents that make up the wood gradually dissolve into the spirit determining its flavour, colour and taste (Tanaka 2010). The wood of American white oak used to make many of the barrels used to age whisky contains significant amounts of an oak wood polyphenols called ellagitannins. The processing stages of making barrel for whisky production, including seasoning and toasting, results in various chemical changes in the ellagitannins of the wood resulting in the phenolic compounds in the whisky being rather different than the original oak wood polyphenols (Cadahia 2001). The original tannins decompose during toasting or charring of the barrels and then during the aging process oxygen molecules are absorbed through the wood further oxidising the dissolved phenolic compounds. The polyphenols in whisky are a mixture of products resulting from a complex chemical process (Tanaka 2010). These non-volatile components of whisky are known are whisky congeners, they are not found in the freshly distilled spirit but rather are a result of the long aging of good whisky. A range of these phenolic compounds were isolated from commercially bottled Japanese whisky including carboxyl ellagic acid, gallic acid, ellagic acid, brevifolin carboxylic acid, among others (Fujieda 2008). In another study ellagic acid, gallic acid, and lyoniresinol were found to be the principle polyphenols in a range of whiskies of both Japanese and Scottish origin. However, these three compounds only made up 20% of the antioxidant capacity of the whisky tested, suggesting there are a range of other polyphenols involved (Koga 2007).

Whisky graph 3

Levels of gallic acid, ellagic acid, and lyoniresinol in whisky of different ages (Fujieda 2008).

Unlike other popular beverages whisky has been rather lacking in study regarding the potential effects of these plant phytochemicals when ingested by humans. One of the few studies on the subject, carried out at my own Rowett Institute, examined the concentration of phenolic compounds and antioxidant capacity of volunteers blood after drinking 100 millilitres, (3.5 ounces) of either red wine, a 12 y old malt whisky which had been matured in oak wood casks, or a `new make’ whisky which is the newly-distilled whisky spirit prior to maturation. Surely one of the more arduous nutrition studies ever carried out (Duthie et al. 1998).

whisky graph 1

Concentration of total phenols in volunteers blood after drinking whisky or red wine (Duthie 1998).

Both the whisky and red wine produced a similar rise in total phenols in the blood of volunteers, suggesting the phenolic compounds in whisky are rapidly absorbed after drinking. The ‘new make’ whisky did not cause any rise in blood phenols. Although the levels in the blood were similar between red wine and whisky, in fact proportionately more of the phenolic compounds were absorbed from the whisky than the wine. This may be due to the higher alcohol content enhancing their absorption, and different bioavailability of the compounds in wine and whisky. New made whisky did not result in any increase in phenols in the volunteers’ blood (Duthie et al. 1998).

Whisky graph 2

Antioxidant capacity of volunteers blood after drinking whisky or red wine (Duthie 1998).

Drinking whisky or red wine increase the antioxidant capacity of the volunteers’ blood to a similar degree. Unexpectedly the ‘new make’ whisky caused a decrease in antioxidant capacity of the blood, possibly due to increased oxidative stress caused by the alcohol itself, or as suggested by the authors, the greater content of copper in the ‘new make’ whisky. This suggested that the phenolic compounds in whisky are absorbed and can influence the antioxidant capacity of the blood in a similar way to red wine, and that the aging process of whisky in oak barrels in key to these effects.

The phenolic compounds in whisky appear to be absorbed into the blood and a few small studies from Japan now hint at what effects these compounds may have in the body. Single malt whisky showed the ability to neutralise free radicals and there was a positive correlation between this activity and the how long the whisky had been aged (Koga 2007).  This antioxidant ability of whisky has been found to protect E. coli bacteria from oxidative damage caused by hydrogen peroxide, compared to the same amount of pure alcohol (Aoshima 2004). The specific compounds isolated from whisky have been shown to have a range of interesting effects. Isolated whisky phenolic compounds including ellagic acids suppressed allergic reactions to allergens in both isolated cells and in mice. These findings suggest that the phenolic compounds from whisky seemed to be beneficial to ameliorate allergic reactions (Itoh 2010). The isolated phenolic compounds from whisky were found to reduce the inflammation in isolated immune cells and in mice. These whisky phenolic compounds may be beneficial for the treatment of inflammatory disease (Itoh 2012). Ellagic acid prevented alcohol induced development of fatty liver in mice, although these were higher doses than found in whisky. These results provide a molecular basis for the prevention of alcohol-induced stress by the polyphenols in alcoholic beverages (Yao 2014). In human epithelial cells, the cells that line the blood vessels of the body, the activity of the enzyme heme oxygenase-1 was increased by the phenolic compounds isolated from whisky.  This effect only emerged in whisky aged in oak barrels. This heme oxygenase-1 enzyme is thought to protect the lining of the blood vessels from damage. Various epidemiological reports suggest a moderate consumption of alcoholic beverages appears to reduce some health risks in relation to human health. The, up-regulation of this enzyme in the cells lining the blood vessels by whisky might possibly contribute to the maintenance of blood vessel function (Suzuki 2010). These effects are interesting but should however be taken with some caution as the relevance of the potential effects, in the concentrations found in whisky, are unknown to human health.

The phenolic compound ellagic acid may have a direct effect in the gut ameliorating some of the harmful effects of alcohol on the lining of the gut. It has been shown that whisky is less irritating to the delicate lining of the gut, as compared with pure ethanol. This effect of whisky may be explained by ellagic acid, one of major polyphenols contained in whisky, and its radical scavenging action (Iino 2001). A later study confirmed that ellagic acid is able to directly protect the lining of the gut from damage and explains the less damaging effect of whisky on the stomach than pure alcohol (Iino 2002).  This is hardly to suggest that whisky is good for the gut, but at least its potential negative effects are mitigated by its polyphenols compared to pure alcohol.

The effect of whisky of uric acid levels in the blood has also been investigated. Alcohol generally increases the level of uric acid in the blood, both by increasing the production of uric acid in the liver and reducing how much is excreted in urine. This a concern for people with high blood uric acid levels who are at risk of gout, for which alcohol consumption is an important risk factor. However, unlike other alcoholic drinks, it has been found that whisky tended to lower the levels of uric acid in the blood (Nishioka 2002). This tendency was suggested to be partly due to the inhibition of xanthine oxidase, the enzyme that produces uric acid. The longer the whisky had been aged in oak casks the greater effect it had on reducing the activity of the xanthine oxidase enzyme. It was also found that whisky stimulated an increase in the amount of uric acid excreted in the urine by 27%. This improved excretion of uric acid seemed to be mainly responsible for the reduced uric acid after drinking whisky and showed that at a moderate level of drinking, whisky have different effects on uric acid than other types of alcohol (Nishioka 2002). More recently it has been suggested that the decreased serum urate level after whisky consumption may be mainly due to inhibition the uric acid transporters in the kidneys by the phenolic congeners in whisky. This would result in more uric acid being lost into the urine (Lu 2014). While this may make whisky a better choice than other drinks to those with  high blood uric acid levels or gout who wish to drink alcohol, caution should be applied, as the research on this subject is rather limited.

While these phenolic compounds may be appearing rather good now, there is a possible downside to their presence in whisky. Some older research (Damrau 1960), suggests that the same whisky congeners absorbed from the oat barrels can slow the metabolism of alcohol. This could explain the increased hangover symptoms reported by volunteers in the study, at least in comparison to vodka.

It is clear that aged malt whisky does contain phenolic compounds, originating from the oak wood barrels, and shaped by the long maturing of the whisky. These compounds, such as ellagic acid, do have the potential to beneficially affect the health of those imbibing of these spirits, above that pure alcohol would have on its own. These various phenols can potentially have a range of effects on our physiology, although it is still unclear how relevant these may be to our health. To quote one of the papers on this topic,

“We do not recommend drinking whiskey or wine as a method of antioxidant intake, since other beverages such as green tea and oolong tea also include many antioxidants such as catechin derivatives. However, you can think of the antioxidative activity of whiskey or wine if you often drink liquors. More epidemiological studies are also necessary to clarify whether the antioxidants in liquors are related favourably to human mortality.” – (Aoshima 2004)

It does maybe provide an excuse for the purchase of an older, longer matured, fine malt whisky. Perhaps be cautious with drinking to excess, as those very same compounds may increasing any resulting hangover.

 

Conflicts of interest: I do rather like good whisky.

References
Aoshima, H., Tsunoue, H., Koda, H. & Kiso, Y. 2004, “Aging of whiskey increases 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity“, Journal of Agricultural and Food Chemistry, vol. 52, no. 16, pp. 5240-5244.
“1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of Japanese whiskey after various aging periods in oak barrels was measured to evaluate the antioxidative effects of whiskey. The activity of the whiskey increased with the aging period with high correlation. The activity of various types of whiskey was measured and shown to be correlated to the potentiation of the GABAA receptor response measured in a previous paper. However, the fragrant compounds in the whiskey which potentiated the GABAA receptor response had low DPPH radical scavenging activity, while phenol derivatives had high radical scavenging activity. The whiskey was extracted by pentane. The aqueous part showed the scavenging activity, whereas the pentane part did not. Thus, both the DPPH radical scavenging activity and the potentiation of the GABAA receptor response increased during whiskey aging in oak barrels, but were due to different components. The whiskey protected the H2O2-induced death of E. coli more than ethanol at the same concentration as that of the whiskey. The changes that occurred in the whiskey during aging may be the reason aged whiskies are so highly valued.
Cadahia, E., Varea, S., Munoz, L., de Simon, B. & Garcia-Vallejo, M. 2001, “Evolution of ellagitannins in Spanish, French, and American oak woods during natural seasoning and toasting“, Journal of Agricultural and Food Chemistry, vol. 49, no. 8, pp. 3677-3684.
“The evolution of tannins in Spanish oak heartwood of Quercus robur L., Quercus petraea Liebl.,Quercus pyrenaica Wild., and Quercus faginea Lam. was studied in relation to the processing of wood in barrel cooperage. Their evolution was compared with that of French oak of Q. robur (Limousin, France) and Q. petraea (Allier, France) and American oak of Quercus alba L. (Missouri), which are habitually used in cooperage. Two stages of process were researched: the seasoning of woods during 3 years in natural conditions and toasting. Total phenol and total ellagitannin contents and optical density at 420 nm of wood extracts were determined. The ellagitannins roburins A-E, grandinin, vescalagin, and castalagin were identified and quantified by HPLC, and the molecular weight distribution of ellagitannins was calculated by GPC. During the seasoning process the different ellagitannin concentrations decreased according to the duration of this process and in the same way as those in French and American woods. The toasting process also had an important influence on the ellagitannin composition of wood. Roburins A-E, grandinin, vescalagin, and castalagin decreased during this process in the Spanish wood species, in the same proportion as in the French and American ones. Also, the seasoning and toasting processes lead to qualitative variations in the structure of ellagitannins, especially in the molecular weight distribution, as was evidenced by GPC analysis of their acetylated derivatives.”
Damrau, F.,Liddy, E. 1960, “Hangovers and Whisky Congeners: Comparison of Whisky with Vodka“, Journal of the National Medical Association, vol. 52, no. 4, pp. 262–265.
“IN a field survey’ of moderate social drinkers, many of the persons interviewed reported less hangover with vodka as compared with the same amount of whisky. Further studies established an important role of the whisky congeners in causing hangover.2 Investigation of the toxicology of whisky congeners2 demonstrated that, even in as small amount as 2 ounces of whisky, the congeners increase and prolong the action of alcohol and often produce definite after-effects lasting into the following day. These after-effects were absent or minimal when the same amount of alcohol was consumed in the form of vodka.* The present report deals with mild hangovers occurring in unaccustomed or social drinkers. In this study the term “hangover” is used according to its general definition :3 namely, “headache, nausea, etc. occurring as an after-effect of drinking much alcoholic liquor.” More specifically, we have concentrated our attention on the after-effects of small quantities of whisky and vodka, respectively, so as to eliminate the overshadowing effects of large excesses of alcohol. In this way we have been able to demonstrate a definite difference between whisky and vodka with reference to the occurrence of mild hangovers in unaccustomed and social drinkers. The results can be attributed to the great difference in their congeneric content as shown in Table 1.”
Duthie, G., Pedersen, M., Gardner, P., Morrice, P., Jenkinson, A., McPhail, D. & Steele, G. 1998, “The effect of whisky and wine consumption on total phenol content and antioxidant capacity of plasma from healthy volunteers“, European Journal of Clinical Nutrition, vol. 52, no. 10, pp. 733-736.
“OBJECTIVE: To assess whether consumption of 100 ml of whisky or red wine by healthy male subjects increased plasma total phenol content and antioxidant capacity.
DESIGN: A Latin square arrangement to eliminate ordering effects whereby, after an overnight fast, nine volunteers consumed 100 ml of red wine, malt whisky or unmatured ‘new make’ spirit. Each volunteer participated on three occasions one week apart, consuming one of the beverages each time. Blood samples were obtained from the anticubital vein at intervals up to 4h after consumption of the beverages when a urine sample was also obtained.
RESULTS: Within 30 min of consumption of the wine and whisky, there was a similar and significant increase in plasma total phenol content and antioxidant capacity as determined by the ferric reducing capacity of plasma (FRAP). No changes were observed following consumption of ‘new make’ spirit.
CONCLUSIONS: Consumption of phenolic-containing alcoholic beverages transiently raises total phenol concentration and enhances the antioxidant capacity of plasma. This is compatible with suggestions that moderate alcohol usage and increased antioxidant intake decrease the risk of coronary heart disease.”
Fujieda, M., Tanaka, T., Suwa, Y., Koshimizu, S. & Kouno, I. 2008, “Isolation and structure of whiskey polyphenols produced by oxidation of oak wood ellagitannins“, Journal of Agricultural and Food Chemistry, vol. 56, no. 16, pp. 7305-7310.
“Three new phenolic compounds named whiskey tannins A and B and carboxyl ellagic acid were isolated from commercial Japanese whiskey, along with gallic acid, ellagic acid, brevifolin carboxylic acid, three galloyl glucoses, a galloyl ester of phenolic glucoside, 2,3-(S)-hexahydroxydiphenoylglucose, and castacrenin B. Whiskey tannins A and B were oxidation products of a major oak wood ellagitannin, castalagin, in which the pyrogallol ring at the glucose C-1 position of castalagin was oxidized to a cyclopentenone moiety. These tannins originated from ellagitannins contained in the oak wood used for barrel production; however, the original oak wood ellagitannins were not detected in the whiskey. To examine whether the whiskey tannins were produced during the charring process of barrel production, pyrolysis products of castalagin were investigated. Dehydrocastalagin and a new phenolcarboxylic acid trislactone having an isocoumarin structure were isolated, along with castacrenin F and ellagic acid. However, whiskey tannins were not detected in the products.”
Iino, T., Nakahara, K., Miki, W., Kiso, Y., Ogawa, Y., Kato, S. & Takeuchi, K. 2001, “Less damaging effect of whisky in rat stomachs in comparison with pure ethanol – Role of ellagic acid, the nonalcoholic component“, Digestion, vol. 64, no. 4, pp. 214-221.
“BACKGROUND/AIM: Ellagic acid (EA), one of the polyphenols that are abundantly contained in whisky as a nonalcoholic component, has antioxidant and anti-inflammatory activities. In the present study, we compared the action of whisky and pure ethanol on the rat gastric mucosa, and examined the role of EA in the less-damaging effect of whisky in the stomach.
METHODS: Under urethane anesthesia, a rat stomach was mounted in an ex vivo chamber, perfused with saline, and the transmucosal potential difference (PD) was measured before and after exposure to whisky (Yamazaki, Suntory) and ethanol (43%). In a separate study, the animals were given whisky or ethanol (1 ml, 43%) p.o. under unanesthetized conditions, killed 1 h later, and the gastric mucosa was examined for hemorrhagic lesions.
RESULTS: Both whisky and ethanol caused a PD reduction, resulting in damage in the stomach, but these responses were less marked in the case of whisky. Although the reduced PD recovered gradually after removal of ethanol, this process was significantly expedited by co-application of EA (80 microg/ml), the recovery rate being much the same as that observed after exposure to whisky. The less-damaging effect of whisky was confirmed in unanesthetized rats after p.o. administration of these agents. In addition, EA (1-30 mg/kg), administered p.o. together with absolute ethanol (99.9%), reduced the severity of gastric lesions induced by ethanol, in a dose-dependent manner, and the effect at 30 mg/kg was equivalent to that obtained by the whisky component containing several low- and high-molecular-weight polyphenols. EA had a scavenging action against both oxygen and hydroxyl radicals in vitro, the effect being equivalent to that of catechol or alpha-tocopherol.
CONCLUSION: These results suggest that whisky is less irritating to the gastric mucosa, as compared with pure ethanol, and this property of whisky may be explained by EA, one of polyphenols contained in whisky, and its radical scavenging action.
Iino, T., Tashima, K., Umeda, M., Ogawa, Y., Takeeda, M., Takata, K. & Takeuchi, K. 2002, “Effect of ellagic acid on gastric damage induced in ischemic rat stomachs following ammonia or reperfusion“, Life Sciences, vol. 70, no. 10, pp. 1139-1150.
“We examined the effect of ellagic acid (EA), one of the polyphenols that are abundantly contained in whisky as a nonalcoholic component, on gastric lesions induced by ammonia plus ischemia or ischemia/reperfusion in rats, in relation to the antioxidative system. Under urethane anesthesia, a rat stomach was mounted in an ex vivo chamber, and the following two experiments were performed; 1) a stomach was made ischemic (1.5 ml/100 g body weight) for 20 min, followed by reperfusion for 15 min in the presence of 100 mM HCl; 2) a stomach was made ischemic by bleeding from the carotid artery (1 ml/100 g body weight), followed by intragastric application of ammonia (NH4OH: 120 mM). EA (0.1-10 mg/ml) was applied in the chamber 30 min before the onset of ischemia. Gastric potential difference (PD) and mucosal blood flow (GMBF) were measured before, during and after 20 min of ischemia. Ischemia/reperfusion caused a profound drop in GMBF followed by a return, and resulted in hemorrhagic lesions in the stomach in the presence of 100 mM HCI. These lesions were dose-dependently prevented by EA with suppression of lipid peroxidation but no effect on GMBF, and the effect at 6 mg/ml was almost equivalent to that of superoxide dismutase (SOD: 15000 unit/kg/hr) infused i.v. during a test-period. On the other hand, application of NH4OH to the ischemic stomach produced a marked reduction in PD, resulting in severe hemorrhagic lesions. These changes were prevented with both EA and SOD. In addition, EA had a potent scavenging action against monochloramine in vitro. These results suggest that EA exhibits gastric protective action against gastric lesions induced by NH4OH or reperfusion in the ischemic stomach, probably due to its anti-oxidative activity. This property of EA partly explains the less damaging effect of whisky in the stomach and may be useful as the prophylactic for Helicobacter pylori-associated gastritis.
Itoh, T., Ando, M., Tsukamasa, Y., Wakimoto, T. & Nukaya, H. 2012, “Whiskey Congeners Suppress LPS/IFN gamma-Induced NO Production in Murine Macrophage RAW 264 Cells by Inducing Heme Oxygenase-1 Expression“, Journal of Agricultural and Food Chemistry, vol. 60, no. 51, pp. 12491-12500.
Whiskey includes many nonvolatile substances (whiskey congeners; Whc) that seep from the oak cask during the maturation process. To date, many functions of Whc have reported, such as antiallergy and antimelanogenesis. This study examined the effect of Whc on LPS/IFNγ-induced nitric oxide (NO) production in murine macrophage RAW 264 cells. Whc suppressed LPS/IFNγ-induced NO production in a concentration-dependent manner. To determine the active compounds in Whc, the effect of 10 major compounds isolated from Whc on LPS/IFNγ-induced NO production was examined. Coniferylaldehyde (CA) and sinapylaldehyde (SiA) strongly suppressed LPS/IFNγ-induced NO production. Pretreatment with Whc, CA, and SiA induced heme oxygenase-1 (HO-1) expression. The expression of HO-1 by Whc, CA, and SiA pretreatment was due to activation of Nrf2/ARE signaling via the elevation of intracellular reactive oxygen species. To investigate the in vivo effects of Whc, Whc was administered to mice with antitype II collagen antibody-induced arthritis, and we the arthritis score and hind paw volume were measured. Administration of Whc remarkably suppressed the arthritis score and hind paw volume. Taken together, these findings suggest that Whc is beneficial for the treatment of inflammatory disease.
Itoh, T., Tsukane, M., Koike, M., Nakamura, C., Ohguchi, K., Ito, M., Akao, Y., Koshimizu, S., Nozawa, Y., Wakimoto, T., Nukaya, H. & Suwa, Y. 2010, “Inhibitory Effects of Whisky Congeners on IgE-Mediated Degranulation in Rat Basophilic Leukemia RBL-2H3 Cells and Passive Cutaneous Anaphylaxis Reaction in Mice“, Journal of Agricultural and Food Chemistry, vol. 58, no. 12, pp. 7149-7157.
“Whisky is matured in oak casks. Many nonvolatile substances (whisky congeners, WC) seep from the oak cask during the maturing process. In this study, three antiallergic agents (syringaldehyde, SA; lyoniresinol, Lyo; and ellagic acid, EA) were isolated from WC. Treatment with SA, Lyo, and EA reduced the elevation of intracellular free Ca(2+) concentration ([Ca(2+)]i) and intracellular ROS production caused by FcepsilonRI activation. The inhibitions of the elevation of [Ca(2+)]i and intracellular ROS production by SA and Lyo were mainly due to the suppression of the NADPH oxidase activity and scavenging of the produced radical, respectively. On the other hand, EA inactivated spleen tyrosine kinase and led to the inhibition of the elevation of [Ca(2+)]i and intracellular ROS production. Furthermore, it was found that WC strongly inhibited IgE binding to the FcepsilonRIalpha chain, whereas SA, Lyo, and EA did not indicate this inhibitory effect. These results suggest that WC inhibits allergic reactions through multiple mechanisms. To disclose the in vivo effects of WC, SA, Lyo, and EA, these compounds were administered to type I allergic model mice, and the passive cutaneous anaphylaxis (PCA) reaction was measured. These compounds remarkably suppressed the PCA reaction. Taken together, these findings suggest that WC seemed to be beneficial to ameliorate allergic reactions.
Koga, K., Taguchi, A., Koshimizu, S., Suwa, Y., Yamada, Y., Shirasaka, N. & Yoshizumi, H. 2007, “Reactive oxygen scavenging activity of matured whiskey and its active polyphenols“, Journal of Food Science, vol. 72, no. 3, pp. S212-S217.
“The quality of whiskey is known to improve remarkably by its storage over many years. This process is commonly termed “maturing.” In this process, polyphenols derived from lignin and tannin of the barrel have an important role in not only forming the matured flavor and taste but also contributing to the advance of clustering ethanol and water in whiskey. It is also likely that polyphenols generally possess reactive oxygen (RO) scavenging activity. The present study evaluated the RO scavenging activity (free-radical scavenging activity, H(2)O(2) reduction activity under peroxidase coculture, and H(2)O(2)scavenging activity) of 24 single malt whiskeys with a maturation age of 10 to 30 y produced in Japanese, Scotch (Islay), or Scotch (Speyside and Highland) regions. Single malt whiskey not only showed RO scavenging activity but there was also a positive correlation between this activity and the maturation age of whiskey exceeding the difference resulting from the manufacturing region. A nonvolatile fraction derived from the barrel was responsible for RO scavenging activity. In particular, the contents of ellagic and gallic acids and lyoniresinol, the main polyphenolic compounds in whiskey, increased with maturation age. For the free-radical scavenging activity per molecule, each compound was 1.68 to 3.14 times that of trolox (a water-soluble vitamin E). The activities of ellagic acid, gallic acid, and lyoniresinol in the whiskey (Yamazaki 18) were equivalent to that of 80.3, 31.2, and 11.1 ppm trolox, respectively. Accordingly, the total activity of these 3 compounds accounted for about 20% of the activity of the whiskey (630.7 ppm trolox).”
Lu, Y., Nakanishi, T., Fukazawa, M. & Tamai, I. 2014, “How Does Whisky Lower Serum Urate Level?”, Phytotherapy Research, vol. 28, no. 5, pp. 788-790.
“Clinical studies have shown that moderate whisky consumption increased renal excretion of urate into urine and decreased serum urate level, but the mechanism involved has not been established. Because renal reabsorption influences serum urate level, the effects of the whisky congeners on urate transporters, urate transporter 1 (URAT1), and voltage-driven urate transporter (URATv1) involved in reabsorptive transport of urate were examined. In transporter-expressing Xenopus oocytes, 12-year-old and 18-year-old whisky congeners inhibited urate uptake by URAT1 with IC50 values of 0.08 ± 0.01 and 0.04 ± 0.01 mg/mL, respectively, while urate uptake by URATv1 was inhibited only at 1 mg/mL. Decreased serum urate level after whisky consumption may be mainly due to inhibition of URAT1 by the congeners.
Nishioka, K., Sumida, T., Iwatani, M., Kusumoto, A., Ishikura, Y., Hatanaka, H., Yomo, H., Kohda, H., Ashikari, T., Shibano, Y. & Suwa, Y. 2002, “Influence of moderate drinking on purine and carbohydrate metabolism“, Alcoholism-Clinical and Experimental Research, vol. 26, no. 8, pp. 20S-25S.
BACKGROUND: We examined the influences of a moderate intake level of three types of alcoholic beverages–beer, whisky, and Shochu (Japanese distilled liquor)–on purine and carbohydrate metabolism and excretion in healthy male volunteers, concerning (1) the extent of contribution of purine bodies contained in beer to uric acid metabolism and (2) a comparison between two types of distilled spirits with (whisky) and without (Shochu) aging in oak wood barrel storage.
METHODS: Three sets of studies were conducted in which 10 to 13 healthy adult men were instructed to drink three types of alcoholic beverages at a slightly higher level (0.8 ml of ethanol equivalent/kg body weight) than moderate drinking (approximately 30.4 ml or less for men). A low purine beer was test-manufactured by treating nucleosides that were contained in wort and remained in beer with purine nucleoside phosphorylase derived from Ochrobacterium anthropi, thereby converting them into corresponding purine bases that were easily assimilated by beer yeast.
RESULTS: Although beer intake enhanced the level of serum uric acid by 13.6%, blood glucose by 26.7%, and insulin level by 5.1-fold, drinking a moderate level of distilled liquor (whisky, Shochu) did not increase the serum uric acid level or the other two parameters. The serum uric acid level observed after drinking beer with a purine body concentration reduced by 28% (68% in nucleosides and purine bases) was almost identical to the level observed after drinking regular beer. Whisky has been found to have a property that decreases the serum uric acid level. Excretion of uric acid from blood is increased by 27% after drinking whisky.
CONCLUSIONS: Moderate drinking of distilled liquors did not enhance serum uric acid level, blood glucose, or insulin level in healthy male subjects. Increased serum uric acid after beer intake could not be explained mostly with their purine body congeners. Whisky showed the eliminative property in serum uric acid through excretion of it from blood to urine. At a moderate drinking level, beer and whisky have different effects on purine metabolism or excretion.”
Suzuki, K., Nemoto, A., Tanaka, I., Koshimizu, S., Suwa, Y. & Ishihara, H. 2010, “Induction of Heme Oxygenase-1 by Whisky Congeners in Human Endothelial Cells“, Journal of Food Science, vol. 75, no. 6, pp. H163-H166.
“It is expected that the production of the cytoprotective heme oxygenase-1 (HO-1) protein in endothelial cells would reduce severity of vascular injuries, while phenolic compounds are known to induce HO-1 mRNA and protein in various cells. We investigated the activation of HO-1 by whisky, which contains various phenolic substances. The congeners of whisky stored from 4 to 18 y in oak barrels were shown to induce an increase of HO-1 protein in human umbilical vein endothelial cells, while those of freshly distilled whisky spirit exhibited no activity. To determine the compounds with potent HO-1-inducing activity among the whisky congeners, several chemicals that had been reported to exist in whisky or oak barrels were screened, and coniferyl aldehyde and sinapyl aldehyde showed the activity. Thus, compounds that emerged in whisky during barrel storage induced cytoprotective protein, HO-1, in human endothelial cells.”
Tanaka, T., Matsuo, Y. & Kouno, I. 2010, “Chemistry of Secondary Polyphenols Produced during Processing of Tea and Selected Foods“, International Journal of Molecular Sciences, vol. 11, no. 1, pp. 14-40.
“This review will discuss recent progress in the chemistry of secondary polyphenols produced during food processing. The production mechanism of the secondary polyphenols in black tea, whisky, cinnamon, and persimmon fruits will be introduced. In the process of black tea production, tea leaf catechins are enzymatically oxidized to yield a complex mixture of oxidation products, including theaflavins and thearubigins. Despite the importance of the beverage, most of the chemical constituents have not yet been confirmed due to the complexity of the mixture. However, the reaction mechanisms at the initial stages of catechin oxidation are explained by simple quinone–phenol coupling reactions. In vitro model experiments indicated the presence of interesting regio- and stereoselective reactions. Recent results on the reaction mechanisms will be introduced. During the aging of whisky in oak wood barrels, ellagitannins originating from oak wood are oxidized and react with ethanol to give characteristic secondary ellagitannins. The major part of the cinnamon procyanidins is polymerized by copolymerization with cinnamaldehyde. In addition, anthocyanidin structural units are generated in the polymer molecules by oxidation which accounts for the reddish coloration of the cinnamon extract. This reaction is related to the insolubilization of proanthocyanidins in persimmon fruits by condensation with acetaldehyde. In addition to oxidation, the reaction of polyphenols with aldehydes may be important in food processing.”
Yao, R., Yasuoka, A., Kamei, A., Ushiama, S., Kitagawa, Y., Rogi, T., Shibata, H., Abe, K. & Misaka, T. 2014, “Nuclear Receptor-Mediated Alleviation of Alcoholic Fatty Liver by Polyphenols Contained in Alcoholic Beverages“, Plos One, vol. 9, no. 2, pp. e87142.
“To elucidate the effect of the polyphenols contained in alcoholic beverages on the metabolic stress induced by ethanol consumption, four groups of mice were fed for five weeks on Lieber’s diet with or without ethanol, with ethanol plus ellagic acid, and with ethanol plus trans-resveratrol. Alcoholic fatty liver was observed in the group fed the ethanol diet but not in those fed the ethanol plus polyphenol diets. Liver transcriptome analysis revealed that the addition of the polyphenols suppressed the expression of the genes related to cell stress that were up-regulated by ethanol alone. Conversely, the polyphenols up-regulated the genes involved in bile acid synthesis, unsaturated fatty acid elongation, and tetrahydrofolate synthesis that were down-regulated by ethanol alone. Because parts of these genes were known to be regulated by the constitutive androstane receptor (CAR), we performed the same experiment in the CAR-deficient mice. As a result, fatty liver was observed not only in the ethanol group but also with the ethanol plus polyphenol groups. In addition, there was no segregation of the gene expression profiles among these groups. These results provide a molecular basis for the prevention of alcohol-induced stress by the polyphenols in alcoholic beverages.”
Posted in Articles, Drink, Nutrition, Scottish | 6 Comments