Studies in Adults With Normal Cholesterol Levels
It is important to note that consumption of soy protein does not appear to have a hypocholesterolemic effect in adults with low or normal cholesterol levels. Therefore, there is no need for concern that soy could cause dangerously low cholesterol levels. In a study of 12 adults with a mean total cholesterol level of 145 mg/dL at baseline, the incorporation of 66 to 80 g soy protein (meat replaced by soy analogues and milk replaced by soy beverage) resulted in no significant changes in serum lipids.10 Other investigators who studied the effect of soy protein as part of a hypocaloric diet found significantly lower total and LDL cholesterol compared with a conventional hypocaloric diet.11 12 Sacks et al13 found no significant change in serum lipids in 13 strict vegetarians whose baseline cholesterol was 129 mg/dL. Wong et al14 found no significant change in 13 normocholesterolemic men 20 to 50 years of age (mean baseline total cholesterol, 169 mg/dL) who consumed 50 g soy protein in addition to a diet low in saturated fat and cholesterol. In the meta-analysis of the effect of soy protein on serum cholesterol levels by Anderson et al,8 no significant effect of soy protein was found for those with a cholesterol