Lipoprotein Response to Diets High in Soy or Animal Protein With and Without Isoflavones in Moderately Hypercholesterolemic Subjects

OBJECTIVE—The objective of this study was to assess the independent effect of soy relative to common sources of animal protein and soy-derived isoflavones on blood lipids. METHODS AND RESULTS—Forty-two subjects with LDL cholesterol levels ≥3.36 mmol/L were fed each of four diets in randomized order for 6 weeks per phase. Diets contained a minimum of 25 g animal protein or isolated soy protein/4.2 MJ, with each containing trace amounts or 50 mg of isoflavones/4.2 MJ. Soy protein had a modest effect on total, LDL and HDL cholesterol, and triglyceride concentrations (−2%, P =0.017; −2%, P =0.042; +3%;P =0.034, −11%, P