Consumption of Soymilk Lowers Atherogenic Lipid Fraction in Healthy Individuals

Abstract

The effect of soy-based products on lipid profile has not been well established. Whereas some investigators have reported that soy is hypocholesterolemic, others could only demonstrate this in hypercholesterolemic subjects, while a few have not found any marked association between soy and cholesterol levels. This study was therefore aimed at investigating the effect of soymilk on lipid and lipoprotein profile of normocholesterolemic, apparently healthy Nigerian Africans. Five hundred milliliters of soymilk preparation was consumed daily by 42 apparently healthy young to middle-aged subjects for a period of 21 days. Forty-two other volunteers with similar characteristics, who did not drink the soymilk over this time frame, were randomly selected as controls. Plasma total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), and triglyceride (TG) concentrations were determined twice by standard spectrophotometric methods (at the initial visit and after 3 weeks). Low-density lipoprotein-cholesterol (LDL-C) was calculated from the TC, TG, and HDL-C concentrations. After 21 days, regulated soymilk consumption significantly reduced mean plasma TC by 11% and LDL-C by 25% (P < .001 and P < .001, respectively) and increased mean plasma HDL-C by 20% (P < .05) in the test population. Plasma TG was not significantly altered. In control subjects, no significant differences were observed in mean TC, LDL-C, HDL-C, and TG. Daily consumption of soymilk significantly decreased atherogenic plasma cholesterol concentration. This suggests that soy drink could be an important non-pharmacological cholesterol-reducing agent.