Washington, Aug. 7 - A recent study by Dr. Alicia Thorpe confirms soyfoods lower total cholesterol, even though the author found the reduction in LDL cholesterol was not significant.
The lack of significant LDL reduction could be attributed to the initial LDL cholesterol levels of the subjects, which were nearly within the normal ranges set by the National Heart Lung and Blood Institute. A large cholesterol reduction is not expected in individuals with relatively normal levels. Thorpe notes the study was too under powered to detect a small change. Overall, Thorpe found consumption of soy reduced baseline cholesterols by 5 percent, which is consistent with existing research and the FDA health claim on soy and heart disease.
This study should be considered in a larger context. A recent evidence-based review by Dr. Arline McDonald, with Radiant Research, looked at 35 studies published from 1998 to 2008 that examined soy protein and total cholesterol or LDL cholesterol. McDonald found:
-- A reduction of 4 to 6 percent in LDL cholesterol when consuming 20 to 50 g soy protein daily, when consumed as part of a low fat diet.
-- HDL cholesterol and triglycerides generally saw a favorable change or stayed the same with consumption of soy protein.
-- Reductions in total cholesterol and LDL cholesterol from soy protein consumption was observed in men, women with normal cholesterol levels in pre-menopausal and post-menopausal women and in adults ranging from 25 to 60 years of age.
-- Larger reductions were found in those with higher LDL cholesterol and total cholesterol levels.
Dr. James Anderson, MD, Professor of Medicine and Clinical Nutrition and Emeritus at the University of Kentucky, supplied research that was influential to the original soy protein health claim. Anderson, who also reviewed recent research on soy and cholesterol control, said, "Over the past 10 years clinical trials have reaffirmed the cholesterol-lowering effects of soy protein intake. The ongoing evidence clearly indicates that soy protein intake, at the recommended level, is associated with a serum LDL cholesterol reduction. Thus, consumption of 20 to 25 grams a day of soy protein in divided servings is likely to significantly reduce risk for coronary heart disease events and strokes."