“Eat soy to protect your heart” has been the message from government and private health agencies for the past six years, but the American Heart Association now says it looks like soy has no independent impact on cardiovascular risk.Recent clinical studies have failed to show a protective benefit for soy protein in the diet, and, especially, for taking soy-based isoflavones in supplement form, Harvard School of Public Health nutrition researcher Frank M. Sacks, MD, tells WebMD.Sacks and other members of the AHA nutrition committee reviewed 22 such studies and concluded that eating soy-based foods has only minimal impact on cholesterol and other heart-disease risk factors.The studies indicated that people who ate about 50 grams of soy protein a day, which represented about half of the usual total daily protein intake, reduced LDL, or “bad,” cholesterol by only about 3%. Eating large amounts of soy had no effect on other risk factors such as triglycerides or HDL “good” cholesterol.Combined data from 19 studies assessing isoflavones -- the plant estrogen derived from soy --suggested that isoflavone supplements had no effect on cholesterol at all.
