Soy protein in amounts as small as 20 grams a day can reduce cholesterol and help prevent coronary heart disease, a team of scientists at the University of Illinois has learned in a new study of soy's health effects.The study, published in the American Journal of Clinical Nutrition, was designed to answer a basic question unanswered by previous research efforts: What is the minimum amount of soy protein required for significant reduction of cholesterol?By replacing animal protein with soy protein in diets, the researchers found that cholesterol was lowered in 8l male test patients who received soy doses ranging from 20 to 50 grams daily."Our findings show that consuming as little as 20 grams of soy protein instead of animal protein ... reduces concentrations of (LDL or bad) cholesterol," the university team reported. The researchers noted that the minimum amount of 20 grams is near the 25-gram level recommended to the U.S. Food and Drug Administration when the FDA recently approved labeling of soy products with claims that the products help prevent coronary heart disease.The University of Illinois tests were limited to men aged 23 to 74 years of age. The test subjects were recruited from the Champaign-Urbana, Ill., area. Of the group of 8l men who completed the three-week and six-week test periods, all started with moderately high cholesterol levels and saw them reduced up to five percent during the study period.The minimum soy level of 20 grams daily resulted in LDL cholesterol reductions of almost three percent over six weeks. The reductions were "not accompanied by significant changes" in HDL, or so-called "good," cholesterol, the researchers reported.