Consumers may not know the meaning of polyphenols (compounds with many phenolic hydroxyl groups), but they are familiar with the foods from which they are derived and their reported health benefits. Polyphenols from blueberries, soy, cocoa, and green tea offer multiple advantages, including antioxidant activity, anti-inflammatory effects, weight management, and cardiac health aids. Here is a look at some of these polyphenols and recent research supporting some of their healthful attributes.
Blueberry polyphenols include anthocyanins. Hurst et al. (2010) showed that blueberry polyphenols may be beneficial in alleviating muscle damage caused by oxidative stress. Muscle myotubes were simultaneously challenged with fruit extracts (1-50 μg/mL) and calcium ionophore, hydrogen peroxide, or 2,4-dinitrophenol. Damage was monitored by release of cytosolic enzymes. A blueberry fruit extract displayed a potent and significant dose-dependent protective capacity. Evaluation of the protective capacity of anthocyanin sub-extracts of blueberry fruit and pure individual glycosides suggested that malvidin galactoside and/or glucoside were the active compounds.
Stull et al. (2010) demonstrated that daily dietary supplementation with bioactives from whole blueberries improved insulin sensitivity in obese, nondiabetic, and insulin-resistant men and women. Thirty-two participants were randomized to consume either a smoothie containing 22.5 g blueberry bioactives or a smoothie of equal nutritional value without added blueberry bioactives twice daily for 6 weeks. The mean change in insulin sensitivity improved more in the blueberry group than in the placebo group. The beneficial effects of the blueberries are thought to be linked to their flavonoid content, in particular, anthocyanins and flavanols.
Moghe et al. (2011) concluded that blueberry polyphenols may play an effective role in inhibiting adipogenesis and cell proliferation. Researchers tested the dose-dependent effects of blueberry polyphenols ((BB-150, BB-200, and BB-250 μg/mL) on mouse preadipocyte differentiation and lipolysis. Blueberry polyphenols showed a dose-dependent suppression of adipocyte differentiation. Cell proliferation was observed to be significantly higher in the control than in all of the blueberry polyphenol groups.
Bowtell et al. (2011) showed that Montmorency cherry juice consumption improved the recovery of isometric muscle strength after intensive exercise. Montmorency cherries contain high levels of polyphenolic compounds including flavonoids and anthocyanins possessing antioxidant and anti-inflammatory effects. Researchers gave 10 trained athletes 1 oz of an antioxidant-packed tart cherry juice concentrate twice daily for 7 days prior to an intense round of strength training and for 2 days after it. The athletes’ recovery after the cherry juice concentrate was significantly faster compared to when they drank juice without the same phytonutrient content.
After drinking cherry juice, athletes returned to 90% of normal muscle force at 24 hr, compared to only 85% of normal at the same time point without cherry juice—a significant difference that could affect an athlete’s next bout of performance. In addition to recovery benefits, research also suggests cherries could affect inflammation related to heart disease and arthritis.
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Two recent studies suggested that apples might help in extending the lifespan and helping fight cancer (U.S. Apple Association, 2011). Researchers from the University of Melbourne’s School of Land and Environment found that antioxidants from apple peels and concentrated tomato can possibly help reduce the growth of cervical and liver cancer cells. The researchers stated that they were able to reduce the growth of cancer cells by 85–98% in vitro.
Another study out of the Chinese University of Hong Kong investigated the effect of apple polyphenols (found in the apple’s peel and flesh) on the lifespan of fruit flies. Results indicated the average lifespan was extended by 10% in flies that were fed the apple polyphenols. In addition, they better preserved their ability to walk, climb, and move about. This study opens the door to future trials that will help to determine whether apples have the same impact on humans as they do in animals. In ScienceDaily, the researchers noted that, “the results support those from other studies, including one in which women who often ate apples had a 13–22% decrease in the risk of heart disease, which adds to the apple’s popular cultural image as a healthy food.”
Grape polyphenols such as resveratrol have reported cardioprotective effects. Aoun et al. (2011) showed that a grape polyphenol extract could have anti-diabetic potential. According to the researchers, accumulation of muscle TAG content and modification of muscle phospholipid fatty acid pattern may have an impact on lipid metabolism, increasing the risk of developing diabetes. The study determined whether a grape polyphenol extract (PPE) modulates skeletal muscle TAG content and phospholipid fatty acid composition in rats fed a diet high in fat and high in sucrose (HFHS). The PPE modulated membrane phospholipid fatty acid composition and decreased muscle TAG content in HFHS diet-fed rats. The PPE lowered CD36 gene and protein expression, probably decreasing fatty acid transport and lipid accumulation within skeletal muscle, and increased muscle GLUT4 expression. These effects of the PPE are in favor of better insulin sensitivity.
Cocoa flavanols have been associated with heart health, potentially benefiting cholesterol and blood pressure levels. For nearly two decades, Mars Botanical, Gaithersburg, Md. (www.marsbotanical.com, www.cirku.com), has been studying the process of measuring and maximizing the retention of cocoa flavanols and uncovering their related health benefits. According to the company, cocoa flavanols help keep blood vessels healthy and flexible, supporting good circulation. The cocoa bean is known to naturally contain two flavanol monomers, (-)-epicatechin and (+)-catechin. Both are polyphenols in the sub-class of flavonoids. (-)-Epicatechin, the major flavanol monomer in the cocoa bean, has been shown to be a key component of the cocoa flavanols in relation to circulatory health and healthy nitric oxide production. Procyanidins, also known as proanthocyanidins, are polymers of flavanol monomers such as (-)-epicatechin.
Heiss et al. (2010) demonstrated that regular dietary intake of flavanols improved endothelial dysfunction and increased levels of circulating angiogenic cells (CACs) in patients with coronary artery disease. CACs are critical for vascular repair and maintenance of endothelial function. Sixteen patients received a dietary high-flavanol intervention (375 mg) and a macronutrient- and micronutrient-matched low-flavanol intervention (9 mg) twice daily in random order over 30 days. Results demonstrated a significant increase in flow-mediated vasodilation and a decrease in systolic blood pressure with increasing levels of CACs.
Davison et al. (2008) showed that high-flavanol cocoa (902 mg flavanols) consumption improved endothelial function and may be useful for reducing cardiometabolic risk factors in overweight and obese populations. Impaired endothelial function in obesity may reduce blood flow to sites of metabolism, contributing to impaired fat oxidation and insulin resistance.
Mars is the maker of CirkuHealth™ brand cocoa flavanol supplement products. The cocoa extract in Cirku™ is naturally abundant in cocoa flavanols, containing 350 mg of cocoa flavanols per serving. The scientists at Mars perfected a process to reduce the cocoa bean’s exposure to high temperatures, helping to protect the cocoa extract. This proprietary, patented Cocoapro® process guarantees that the cocoa extract in Mars products has consistent levels of flavanols.
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Soy isoflavones, particularly genistein, have been shown to be beneficial for women’s health, as well as cardiac health. For example, in a meta-analysis of eleven trials, Liu et al. (2011) demonstrated that soy isoflavones had an effect of lowering blood pressure in hypertensive subjects, but not in normotensive subjects. Meta-analysis results showed a mean decrease of 2.5 mm Hg for systolic blood pressure and 1.5 mm Hg for diastolic blood pressure in the soy isoflavones-treated group compared to placebo. In another meta-analysis, Beavers et al. (2010) indicated that exposure to soy isoflavones can modestly, but significantly, improve endothelial function as measured by flow mediation dilation. Endothelial dysfunction has been identified as an independent coronary heart disease risk factor.
Using a patented process, DSM Nutritional Products Inc., Parsippany, N.J. (www.dsmnutritionalproducts.com), has developed a non-soy, nature-identical genistein, geniVida®. It has been shown at the low dose of 30 mg /day to deliver significant health benefits for mature women. In a double-blind, placebo-controlled, multi-center trial, Elliott et al. (2009) showed that geniVida (30 mg daily for 12 weeks) had a significant benefit in reducing the number and duration of daily hot flashes in peri/post-menopausal women and may be used to manage menopausal symptoms without hormone replacement.
To address bone mineral composition loss after menopause, DSM also offers geniVida Bone Blend, a patented combination of genistein, ROPUFA® omega-3 fatty acids EPA and DHA, and the vitamins Quali-D® D-3 and K-1. The blend boosts the body’s natural bone-building process in mature women.
Numerous research studies have evaluated the benefits of green tea, focusing on the polyphenol epigallocatechin gallate (EGCG). The body of scientific evidence shows that EGCG supports cardiovascular health, and aids weight loss by boosting metabolism and fat oxidation. Hill et al. (2007) looked at the metabolic effects of EGCG combined with regular aerobic exercise in 38 overweight or obese female subjects. Subjects took 150 mg of EGCG or placebo twice daily for 12 weeks. Results showed that body composition parameters were reduced in both groups, with no difference between EGCG and placebo, however EGCG significantly decreased resting heart rate and reduced plasma glucose in subjects with impaired glucose tolerance. Researchers concluded that moderate consumption of EGCG can improve the health status of overweight individuals undergoing regular exercise by reducing heart rate and plasma glucose concentrations. Loss of body fat may require a higher intake of EGCG.
Boschmann and Thielecke (2007) suggested that EGCG alone has the potential to increase fat oxidation in men and may thereby contribute to the antiobesity effects of green tea. Six overweight men were given 300 mg EGCG/day for 2 days. Fasting and postprandial changes in energy expenditure (EE) and substrate oxidation were assessed. Resting EE did not differ significantly between EGCG and placebo treatments, although during the first postprandial monitoring phase, respiratory quotient values were significantly lower with EGCG compared to the placebo. Researchers stated that more studies with a greater sample size and a broader range of age and BMI are needed to define the optimum dose.
Most recently, Shen et al. (2011) demonstrated that green tea polyphenols and Tai Chi exercise benefited bone remodeling and muscle strength in postmenopausal osteopenic women through a reduction of oxidative stress damage. In the study, 171 postmenopausal osteopenic women were assigned to four groups: placebo, green tea polyphenols, placebo + Tai Chi, and green tea polyphenols + Tai Chi for 24 weeks. Green tea polyphenol supplementation increased bone-specific alkaline phosphatase (BAP) levels (bone turnover biomarker) after 4 weeks, while Tai Chi exercise increased BAP levels after 12 weeks.
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Teavigo™ Green Tea extract is a natural product extracted through a proprietary process that concentrates the benefits of fresh green tea leaves. This process ensures a minimum of 90% EGCG to maximize healthful benefits. It is caffeine-free, and also free of any herbicide or pesticide residue. Teavigo was developed in Europe by DSM Nutritional Products. Recently, Pharmachem Laboratories Inc., Kearny, N.J., became the exclusive distributor for Teavigo in the dietary supplement marketplace. In addition, Pharmachem is poised to formulate ready-to-drink and powdered drinks containing Teavigo.
Linda Milo Ohr,
Aoun, M., Michel, F., Fouret, G., Schlernitzauer, A., Ollendorff, V., Wrutniak-Cabello, C., Cristol, J.-P., Carbonneau, M.-A., Coudray, C., and Feillet-Coudray, C. 2011. A grape polyphenol extract modulates muscle membrane fatty acid composition and lipid metabolism in high-fat–high-sucrose diet-fed rats. British Journal of Nutrition. Published online ahead of print. doi:10.1017/S0007114511000602.
Beavers, D.P., Beavers, K.M., Miller, M., Stamey, J., and Messina, M.J. 2010. Exposure to isoflavone-containing soy products and endothelial function: A Bayesian meta-analysis of randomized controlled trials. Nutr. Metab. Cardiovasc. Dis. Aug 14. E-pub ahead of print.
Boschmann, M. and Thielecke, F. 2007. The effects of epigallocatechin-3-gallate on thermogenesis and fat oxidation in obese men: a pilot study. J. Am. Coll. Nutr. 26: 389S-395S.
Bowtell, J.L., Sumners, D.P., Dyer, A., Fox, P., and Mileva, K.N. 2011. Montmorency cherry juice reduces muscle damage caused by intensive strength exercise. Medicine & Science in Sports & Exercise. Jan. E-pub ahead of print.
Davison, K., Coates, A.M., Buckley, J.D. and Howe, P.R. 2008. Effect of cocoa flavanols and exercise on cardiometabolic risk factors in overweight and obese subjects. Int. J. Obesity. 32(8): 1289.
Elliott, J., Evans, M., Sharma, P., Berman, R., and Guthrie, N. 2009. Genistein reduces the number and duration of hot flashes in peri/post-menopausal women in a randomized, double-blind, placebo-controlled, multi-center trial. Experimental Biology Late Breaking Abstracts LB471.
Heiss, C., Jahn, S., Taylor, M., Real, W.M., Angeli, F.S., Wong, M.L., Amabile, N., Prasad, M., Rassaf, T., Ottaviani, J.I., Mihardja, S., Keen, C.L., Springer, M.L., Boyle, A., Grossman, W., Glantz, S.A., Schroeter, H., and Yeghiazarians, Y. 2010. Improvement of endothelial function with dietary flavanols is associated with mobilization of circulating angiogenic cells in patients with coronary artery disease. Journal of the American College of Cardiology. 56: 218-224.
Hill, A.M., Coates, A.M., Buckley, J.D., Ross, R., Thielecke, F., and Howe, P.R.C. 2007. Can EGCG reduce abdominal fat in obese subjects? J. Am. Coll. Nutr. 26: 396S-402S.
Hurst, R.D., Wells, R.W., Hurst, S.M., McGhie, T.K., Cooney, J.M., and Jensen, D.J. 2010. Blueberry fruit polyphenolics suppress oxidative stress-induced skeletal muscle cell damage in vitro. Mol. Nutr. Food Res. 54(3): 353-63.
Liu, X.X., Li, S.H., Chen, J.Z., Sun, K., Wang, X.J., Wang, X.G., Hui, R.T. 2011. Effect of soy isoflavones on blood pressure: A meta-analysis of randomized controlled trials. Nutrition, Metabolism and Cardiovascular Diseases. Feb. 8. E-pub ahead of print. doi: 10.1016/j.numecd.2010.09.006.
Moghe, S., Juma, S., and Vijayagopal, P. 2011. Effect of blueberry polyphenols on 3T3-F442A preadipocyte differentiation FASEB J. Meeting Abstract Supplement: 583.7.
Shen, C.-L., Chyu, M.-C., Yeh, J.K., Zhang, Y., Pence, B.C., Felton, C.K., Brismee, J.-M., Dagda, R.Y., Doctolero, S., Flores, M.J., and Wang, J.-S. 2011. Effect of green tea polyphenols and Tai Chi exercise on bone health in postmenopausal women with low bone mass: a 24-week placebo-controlled randomized trial. FASEB J. Meeting Abstract Supplement: 594.3
Stull, A.J., Cash, K.C., Johnson, W.D., Champagne, C.M., and Cefalu, W.T. 2010. Bioactives in blueberries improve insulin sensitivity in obese, insulin-resistant men and women. J. Nutr. 140(9): 1582-7.
U.S. Apple Association. 2011. New research indicates apples may help extend lifespan and fight cancer. Press release, March 9.