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Soy and Cardiovascular Disease Soy basics Food products made from soybeans include tofu, tempeh, soy milk, soy flour, roasted soy nuts, soybeans, and textured soy protein. These foods are low in fat and saturated fat, contain no cholesterol, and are high in fiber. They fit beautifully into a heart-healthy diet. Their protein content is very similar to animal products, making soy products an ideal replacement for meat, chicken, or fish. Research has shown that the amino acid profile of soy protein is almost exactly the same as animal proteins. This means we can use soy protein by itself, without needing to combine it with other types of plant proteins to obtain all essential amino acids. Absorbing soy isn't a problem, either. Soy and heart disease A meta-analysis in 1995 of 38 clinical trials, using soy protein in over one thousand subjects, clearly shows the benefits of soy in preventing heart disease. The studies used 17-124 grams of soy protein per day, with an average intake of 47 grams. Subjects either used soy protein in place of animal protein, or simply added soy products to their diets. The research showed a 9.3 percent decrease in total cholesterol, a 12.9 percent decrease in LDL (low density lipoprotein) cholesterol, and a 10.5 percent decrease in triglycerides. Since every one percent decrease in cholesterol decreases your risk of heart attack by two to three percent, eating soy protein should decrease your risk of heart disease by 18-28 percent. Why does soy protein lower heart disease risk? Scientists have not yet determined the exact mechanisms by which soy protein decreases total cholesterol and LDL cholesterol levels. Many researchers are interested in the phytoestrogen content of soy products. Phytoestrogens, or estrogen-like products found in plants, may improve the flexibility of arteries, decrease the plaque build-up that leads to clots, and prevent the oxidation of LDL cholesterol that injures artery walls and increases plaque production. Researchers are focusing on the role of the specific phytoestrogens genistein, daidzein and glycetein in preventing heart disease. In fact, a recent study presented at the American Heart Association's November 1999 meeting in Atlanta supports the hypothesis. The Women's Ischemia Syndrome Evaluation (WISE) study suggests that increased blood levels of phytoestrogens are linked to beneficial cholesterol levels and improved arterial function in women. Results of the four-year study show significant relationships between the plant products and lower total cholesterol, LDL and HDL cholesterol and triglycerides, according to lead investigator Dr. Noel Bairey Merz. Applying research to food choices The FDA recommends consuming at least 25 grams of soy protein each day for increased cardiovascular health. James Anderson, MD, Professor of Medicine and Clinical Nutrition at the University of Kentucky, and one of the major authors of the meta-analysis, gives the following suggestions: * For general health and prevention of heart disease in people who have no family history of heart disease and no risk factors (smoking, obesity, elevated cholesterol, high blood pressure, sedentary lifestyle, male or female past menopause): Seven servings of soy food products each week, providing 8-10 grams of soy protein per day. * For anyone with a family history of heart disease or more than two risk factors: 14 servings of soy foods each week, providing 16-20 grams of soy protein each day. * For anyone with a diagnosis of heart disease: 21 servings of soy foods each week, providing 24-30 grams of soy protein each day. Tips for adding soy to your diet Scientific evidence clearly shows the health benefits of soy products. Although foods made from soybeans are often foreign to the typical American diet, try to include these foods in our weekly or daily food choices. Try these simple ideas to introduce soy into your diet: * Use soy milk in place of cow's milk on cereal or as a beverage. * Make a smoothie using soy milk or soft tofu and fresh fruit. * Substitute textured soy protein for one-half the ground beef in recipes such as meatballs, spaghetti sauce, or meatloaf. * Substitute tofu for one-half the cheese in lasagna or quiche recipes * Substitute 1/4 cup soy flour for the wheat flour in recipes such as muffins, pancakes, biscuits and breads. * Try snacking on roasted soy nuts instead of pretzels or chips. American Heart Association The American Heart Association is a national voluntary health agency whose mission is to reduce disability and death from cardiovascular diseases and stroke. Date Published: 2002-07-24 |