Jury’s still out on health benefits of wine extract

Red wine extract has leapt into public awareness based on intriguing results from animal studies.

Mice fed the ingredient under study, resveratrol, lived longer and had greater vitality, even with a fatty diet that made them obese. So, should we all rush out to buy resveratrol supplements?

Well, the answer for us humans remains to be seen. At present, the hype far exceeds the proven benefits.

Pssst … I’ve got a secret to share: You can get some of the benefits without the risks when you know the right foods to eat.

What studies show

In a study published a little more than a year ago in Nature, two groups of mice were fed a high-fat, high-calorie diet. The first group received resveratrol supplements and the second group did not.

By the end of the study, the mice fed resveratrol lived longer — adding an equivalent of 10 to 20 human years to their lifespan — despite the fact that they were overweight.

A similar paradox occurs in France. The French eat a rich diet and yet have one of the lowest rates of heart disease in the world. Researchers speculate that the red wine featured in the region’s cuisine helps provide protection for the arteries of the heart.

Resveratrol benefits

But a longer lifespan and lower rate of heart disease are just the beginning. The list of potential benefits in mice includes increased muscle endurance, improved cholesterol levels, fewer blood clots and less risk of diabetes.

The antioxidant and anti-inflammatory effects of resveratrol may also account for a lower rate of age-related memory loss and cancer.

Resveratrol may slow the growth of cancer cells and inhibit the formation of tumors of the lymph nodes, liver, stomach, skin and breast in animal studies, according to the American Institute of Cancer Research.

Other studies indicate that resveratrol leads to the death of leukemia cells and colon cancer tumors, the institute reports.

Potential risks

Sound like a panacea? It may be a cure-all in mice, but very few studies of the extract have been conducted in humans.

The Food and Drug Administration considers resveratrol an investigational new drug not a dietary supplement, since the substance does not have adequate evidence of safety in humans.

Long-term side effects of the wine extract are unknown. Resveratrol has mild estrogenlike properties, making its use unwise for women at increased risk for breast cancer or other hormone-sensitive conditions.

Children and women who are pregnant, nursing or trying to conceive should not take the supplement since it contains factors that may adversely affect growth.

Likewise, people taking blood thinners or other prescription or over-the-counter drugs should not take the product without a doctor’s approval because of the potential for drug interactions.

Recently, ConsumerLab.com published an analysis of 13 resveratrol supplements on the market. Two products contained far less than the listed amount of ingredient and another product had a misleading label. No products were contaminated with lead or cadmium, two types of toxic metals. The report concluded: It’s too early to know whether resveratrol is beneficial to people, what dose is best, and what side effects may occur.

Safest sources

Luckily, Mother Nature packages the substance in whole foods, along with a complementary array of other natural ingredients.

Grape skins boast the highest concentrations of resveratrol. Red and purple grapes contain much more of the substance than green grapes. Other plant sources include red wine, grape seeds, grape juice, berries and peanuts.

For more information: American Institute for Cancer Research, www.aicr.org.

Contact Dr. Elizabeth Smoots, a board-certified family physician and fellow of the American Academy of Family Physicians, at doctor@practicalprevention.com. Her columns are not intended as a substitute for medical advice or treatment. Before adhering to any recommendations in this column consult your health care provider.

&Copy; 2008 Elizabeth S. Smoots