For Immediate Release: August 13, 2009
NW: Questions about phytosterols, whey protein and prostate cancer, Parkinson's risk and diet
Week of September 7, 2009
Contact: Alice Bender, (202) 328-7744
Karen Collins, MS, RD, CDN
American Institute for Cancer Research
Q: Do phytosterols reduce risk of heart disease?
A: Phytosterols, also called plant sterols, are compounds with a chemical structure similar to cholesterol that occur naturally in a variety of plant foods. For people with high blood cholesterol, phytosterols may reduce heart disease risk by decreasing absorption of cholesterol, lowering levels in the blood. Studies show that consuming 2 grams of phytosterols daily can lower LDL (“bad”) cholesterol by about 10 percent. Recently, some research has questioned whether overall heart risk is reduced, but overall recommendations for a cholesterol-lowering strategy do include sterols – or the related compounds called stanols, which have raised no questions. For people with healthy blood cholesterol, phytosterols offer no known benefit for heart health. You can easily accumulate about half a gram (300 to 600 milligrams) of phytosterols from nuts, unrefined vegetable oils, legumes (dried beans and peas), vegetables, fruits and whole grains. Most people are only likely to reach the 2 gram target (2,000 mg) by including two servings of special products such as juices, margarine and salad dressing with extra sterols added.
Q: Does whey protein increase the risk of prostate cancer?
A: Whey protein is a high quality protein derived from milk. It has become a popular protein supplement among body builders, vegetarians, and cancer patients with diminished appetite. Studies aren't yet clear on whether it may offer additional benefits for people with cancer and other diseases, but research does not suggest that its protein is any better than the protein in other foods. I am not aware of any research linking whey with promoting prostate cancer development. Perhaps you have heard that excessive consumption of milk is a concern. A major report by the American Institute for Cancer Research found that diets high in calcium (above 1500 mg per day) probably increase prostate cancer risk. Avoiding excessive amounts of milk and high doses of calcium is suggested, but moderate amounts of dairy and total calcium no more than 1500 milligrams (mg) daily are considered safe.
Q: Can people lower their risk of Parkinson’s disease through diet?
A: For now, research provides no solid evidence that antioxidants, caffeine, coenzyme Q10 or other vitamins or supplements can prevent or treat this progressive, incurable disease of nerve cell damage. Some studies suggest that the healthful, plant-based diet already demonstrated to lower risk of cancer and heart disease may provide benefits but data is still preliminary. Some studies suggest that free radicals that damage blood vessels and DNA of our cells might also activate biochemical pathways that damage neurons. People have shown some reduction in risk of the disease when their diets more closely follow a Mediterranean pattern (high in vegetables, low in red meat, fat mostly monounsaturated fat from olives and olive oil). This eating pattern also often includes fish providing omega-3 fat that may be important for brain health. Studies don’t support antioxidant supplements to lower Parkinson’s risk; and though omega-3 fats are part of a diet that promotes overall health, evidence does not show protection from Parkinson’s with high-dose omega-3 supplements.