Considering that virtually nothing was written about the health benefits of polyphenols before 1995, it continues to amaze me the amount of health benefits this group of nutrients generates. This is primarily due to our growing understanding of how these phytochemicals interact with the most primitive parts of our immune system that have been conserved through millions of years of evolution.
Three new studies add to this growing knowledge. In the January 2011 issue of the American Journal of Clinical Nutrition, it was reported that eating one serving a week of blueberries could reduce the risk of developing hypertension by 10 percent (1). Since a serving size of fruit is defined as ½ cup, that serving size contains about 65 grams of blueberries. Put that into more precise molecular terms, this serving size would provide about 4,000 ORAC units or about the same amount of ORAC units as a glass of wine. The researchers speculated that there was a subclass of polyphenols (which includes delphinidins) that appear to be responsible for most of the effects. So if eating one serving of blueberries (½ cup) once a week is good for reducing the risk of hypertension, guess what the benefits of eating 1 cup of blueberries every day might be? The answer is probably a lot.
Speaking of red wine, in the second study in Biochemical and Biophysical Research Communications researchers found that giving high levels of isolated polyphenols from red wine demonstrated that exercise endurance in older rats could be significantly enhanced. Very good news for old folks like me. They hypothesized the effects may be directly related to “turning on” genes that increase the production of anti-oxidant enzymes (2). The only catch is that the amount of red wine polyphenols required to reach these benefits would equate to drinking about 20-30 glasses of red wine per day.
The final study in Medicine & Science in Sports and Exercise demonstrates that cherry juice rich in polyphenols reduces muscle damage induced by intensive exercise in trained athletes. This reduction in muscle damage was correlated with decreased levels of inflammatory cytokines (3). The reduction of cytokine expression is one of the known anti-inflammatory benefits of increased polyphenol intake.
Three pretty diverse studies, yet it makes perfect sense if you understand how polyphenols work. Polyphenols inhibit the overproduction of inflammatory compounds made by the most ancient part of the immune system that we share with plants. The only trick is taking enough of these polyphenols. To get about 8,000 ORAC units every day requires eating about a cup of blueberries (lots of carbohydrates) or two glasses of red wine (lots of alcohol), or half a bar of very dark chocolate (lots of fat) or 0.3 g of highly purified polyphenol powder in a small capsule (with no carbohydrates, no alcohol, and no saturated fat). And if you are taking extra high purity omega-3 oil, exercising harder, or have an inflammatory disease, you will probably need even more polyphenols. It doesn’t matter where the polyphenols come from as long as you get enough. That’s why you eat lots of colorful carbohydrates on an anti inflammatory diet.
- Cassidy A, O’Reilly EJ, Kay C, Sampson L, Franz M, Forman J, Curhan G, and Rimm EB. “Habitual intake of flavonoid subclasses and incident hypertension in adults.” Am J Clin Nutr 93: 338-347 (2011).
- Dal-Ros S, Zoll J, Lang AL, Auger C, Keller N, Bronner C, Geny B, Schini-Kerth VB. “Chronic intake of red wine polyphenols by young rats prevents aging-induced endothelial dysfunction and decline in physical performance: Role of NADPH oxidase.” Biochem Biophys Res Commun 404: 743-749 (2011).
- Bowtell JL, Sumners DP, Dyer A, Fox P, and Mileva KN. “Montmorency cherry juice reduces muscle damage caused by intensive strength exercise”. Med Sci Sports Exerc 43: online ahead of print doi: 10.1249/MSS.obo13e31820e5adc (2011).