Drink to your Health: Red Wine and Pomegranate Juice

Red Wine and Heart Health

The potential health benefits of wine received wide- spread attention in 1991, when 60 minutes reported on the "French Paradox" - an observation that the French enjoy one of the lowest heart attack rates, despite their penchant for eating lots of saturated fats. While more recent statistics suggest that heart disease in France may have been underestimated in those years, support for alcohol and red wine's apparent heart-healthy role has grown. We're also learning more about how the individual components in wine may contribute to its overall effects.

The Rise of Polyphenols and Resveratrol

The most abundant antioxidants in our diets aren't the ones we're most familiar with, according to Dutch researchers (1). The most plentiful are compounds called polyphenols. About 6000 different flavonoid polyphenols are known, and we may consume as much as a gram of them daily. In contrast, intake of vitamins C, E and beta-carotene combined often amounts to less than 100 mg a day. It is increasingly clear that polyphenols are major contributors to the antioxidant actions of fruits and vegetables.

Wine contains an array of polyphenols, including flavonoids, primarily from the skins of the grapes (which are removed in making white wine). Studies generally show a positive link between dietary flavonoid intake and good health overall, and with cardiovascular health especially (2).

A recently published study (3) suggests that enjoying a glass of wine with fish (both featured in the Mediterranean diet) might maximize omega-3s and explain one way that wine reduces heart disease risk. Moderate wine consumption - 1 glass a day for women, 2 daily for men - was found to boost levels of omega-3 in cell membranes. Because wine had a stronger link with omega-3s than other alcoholic drinks, the scientists think that the polyphenols are key, possibly protecting EPA and DHA from oxidation or stimulating the body to produce more of them.

Trans-resveratrol is another intriguing polyphenol found in grape skins, red wines, and grape juice. In plants, resveratrol acts like an antibiotic, defending the grapevine from disease. Investigators are interested in resveratrol's antioxidant and other properties, as evidenced by its reference in over 2,000 research citations in the National Library of Medicine, including studies at the National Cancer Institute and the National Institute of Aging. One theory holds that polyphenols like resveratrol can help protect the aging brain (4). Another hypothesis is that resveratrol could influence the aging process itself and lead to longer life. Both of these theories need to be confirmed.

Studies have shown that restricting calories increases the lifespan of various animals. It's not clear whether this might hold true in humans where longevity is determined by complex mechanisms, but interest in resveratrol surged when it was found to trigger effects in animals like those prompted by calorie restriction (5).

The Growing Promise of Pomegranates

Pomegranate juice is also chocked full of polyphenols with the capacity to mop up free radicals and interfere with chronic inflammation. This juice, in fact, contains more polyphenols than blueberries, cranberries, green tea, orange juice or even red wine.

Most of the clinical studies exploring the effects of pomegranate juice have been small, but with promising results that warrant further investigation (6,7). Drinking about 2 ounces daily for a year has been shown to reduce the intimal-media thickness of the carotid artery - a measurement of artery walls that's used to track the progression of atherosclerotic disease. In another study, daily intake of about 8 ounces is reported to decrease stress-induced ischemia in patients with heart disease compared to a placebo. It may be that pomegranate polyphenols help protect blood vessels or influence inflammation in artery walls.

References

1. Geleijnse JM, et al. Flavonoids and cardiovascular health: which compounds, what mechanisms? Am J Clin Nutr 88:12, 2008.
2. Erdman JW, et al. Flavonoids and heart health: proceedings of the ILSI North America Flavonoids Workshop, 2005, Washington, DC. J Nutr 137(3 Suppl 1):718S-37S, 2007.
3. de Giuseppe R, et al. Alcohol consumption and n-3 poly-unsaturated fatty acids in healthy men and women from 3 European populations. Am J of Clin Nutr 89:354-62, 2009.
4. Vingtdeux V et, al. Therapeutic potential of resveratrol in Alzheimer's disease. BMC Neurosci 9 Suppl 2:S6, 2008.
5. Barger JL, et al. A low dose of dietary resveratrol partially mimics caloric restriction and retards aging parameters in mice.
6. Basu A, et al. Review, Emerging Science. Pomegranate juice: A heart-healthy fruit juice. Nutr Rev 67:49-56, 2009.
7. Jurenka JS. Review: Therapeutic applications of pomegranate. Altern Med Rev 13:128-44, 2008.