For years the dietary dogmatists have told us to avoid lots of delicious foods. People were supposed to eat brown rice and broccoli and avoid steak, chocolate and nuts. But now the nutrition nay-sayers may have to eat crow.
Walter Willett, MD, PhD, is chairman of the Department of Nutrition at Harvard University School of Public Health. He has declared that the USDA food pyramid should be turned upside down.
Dr. Willett is a big fan of both chocolate and nuts, especially walnuts. In moderation, both have health benefits.
Chocolate is high in flavanoids, plant-based antioxidant compounds similar to those in tea and wine. These flavanoids keep blood platelets from sticking together and reduce the risk of blood clots.
Nuts may be even more beneficial. Dr. Willett and his colleagues have just published a major study (JAMA, Nov. 27, 2002) showing that women who eat 5 ounces or so of nuts a week lower their risk of type 2 diabetes by 27 percent.
This isn’t the first time nuts have been shown to be healthful. It comes on the heels of another study showing that a diet rich in almonds lowers cholesterol without raising blood sugar in diabetics (American Journal of Clinical Nutrition, Nov. 2002).
Other studies have demonstrated a 30 to 50 percent drop in heart disease among people who eat 5 ounces of nuts a week. Almonds, macadamia nuts, hazelnuts and peanuts are all rich in good monounsaturated fats, but walnuts, which contain polyunsaturated fats, may be especially beneficial. The omega-3 fatty acids in walnuts are related to those found in fish oil.
Research indicates that these fats can improve the cholesterol profile. A recent Japanese study showed that bad LDL cholesterol goes down on a diet containing walnuts. The omega-3 fats in walnuts also appear to have antiinflammatory properties. Inflammation is gaining prominence as an important factor in heart disease as well as possibly contributing to Alzheimer’s disease and cancer.
Omega-3 fats may also stabilize heart rhythms. The Physicians Health Study has followed 22,000 male doctors for nearly 20 years. Those who rarely ate nuts were about 50 percent more likely to drop dead suddenly of cardiac arrest (Archives of Internal Medicine, June 24, 2002). Presumably, the men consuming nuts at least twice a week were protected from the changes in heart rhythm that are associated with sudden death.
More good news about nuts came out of a recent presentation to the American Heart Association. Investigators studied the effect of dry-roasted soy nuts on blood pressure in post-menopausal women. Those with hypertension were able to lower their blood pressure by seven percent when they ate half a cup daily. Even women with normal blood pressure experienced a slight drop (3 to 5 percent) by eating soy nuts.
Of course over-indulging in nuts can lead to weight gain. Walnuts have 185 calories in an ounce. But if you substitute nuts for other foods, especially carbohydrates like bread, bagels, crackers or cookies, you can maintain your waistline, reduce your risk of diabetes and keep your heart healthy.
