Week of August 22, 2011
Contact: Alice Bender, (202) 328-7744
Karen Collins, MS, RD, CDN
American Institute for Cancer Research
Q: Is it true that you need to choose red grapes in order to get resveratrol, the compound found in red wine?
A: That is a common misunderstanding. Resveratrol is a phytochemical that in laboratory studies can inhibit cancer development. It is produced by plants to fight off fungal infections and is found in grape skins of all colors. Grapes ferment with skins on to produce red wine, whereas skins are removed before white wine production. This explains the difference in resveratrol content between red and white wines. Overall though, the amount of resveratrol in grapes depends much more on growing conditions than on the color or type of grape. Red grapes also contain anthocyanins, the antioxidant phytochemical that gives them their color. These anthocyanins may also provide other cancer-protective effects in cells. In looking at total antioxidant activity of grapes, studies of green grapes and red grapes show significant levels in each, with red grapes somewhat higher. We need more human studies to understand the potential cancer-protective effects of resveratrol, anthocyanins and other compounds in red and white grapes. Both are excellent choices. Antioxidant effects are just one benefit of the phytochemicals in vegetables and fruits; they also affect cancer development through several separate mechanisms that are not measured by a simple antioxidant score or dependent on content of any one compound.
Q: I keep hearing that the Mediterranean diet is so healthy, but isn't it fattening?
A: The version of Mediterranean-style eating you see in the United States certainly can be fattening. Often we create an Americanized version of Mediterranean dishes, picking the highest calorie options, like dishes made with large amounts of olive oil or baked in rich crusts, adding extra cheese, and serving buttery, honey-soaked pastries for dessert. We ignore the proportions of the traditional Mediterranean diet, which includes plenty of vegetables and beans, little meat, and most frequently fruit for dessert. Also, traditional Mediterranean dishes were designed for people living a very physically active farming life, so we need to adjust the amount of olive oil to meet our more sedentary lives. Several studies link a more Mediterranean diet approach to eating with less yearly weight gain, and the heart of that is filling up on non-starchy vegetables rather than meat, sweets and other "junk food." Don't be afraid of the olive oil and nuts characteristic of the Mediterranean diet, but use them in modest portions to enhance the basic healthy foods on your plate. In a recent analysis of 16 short-term controlled trials of Mediterranean-type diets, getting a few more calories from fat was not a problem for weight loss as long as total calories were controlled – meaning those foods were substituted for others, not just added in. The analysis also shows that including regular physical activity and really sticking with the eating pattern (rather than using it as a quick-fix "diet") also make weight loss with this style of eating more likely.
The American Institute for Cancer Research (AICR) is the cancer charity that fosters research on the relationship of nutrition, physical activity and weight management to cancer risk, interprets the scientific literature and educates the public about the results. It has contributed more than $96 million for innovative research conducted at universities, hospitals and research centers across the country. AICR has published two landmark reports that interpret the accumulated research in the field, and is committed to a process of continuous review. AICR also provides a wide range of educational programs to help millions of Americans learn to make dietary changes for lower cancer risk. Its award-winning New American Plate program is presented in brochures, seminars and on its website, www.aicr.org. AICR is a member of the World Cancer Research Fund International.
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