Once again, studies show that eating whole foods, which naturally provide their own unique combination of nutrients, does more for your health than using supplements.
A meta-analysis of 23 studies published from 1995 to 2002, which appeared in the American Journal of Clinical Nutrition, shows that consumption of soy protein-with its isoflavones intact as it is supplied in soyfoods-results in significant decreases in total cholesterol(by 0.22 mmol/L, or 3.77%), LDL (bad) cholesterol (by 0.21 mmol/L, or 5.25%), and triglycerides (by 0.10 mmol/L, or 7.27%), plus significant increases in HDL (good) cholesterol (by 0.04 mmol/L, or 3.03%).
Reductions in total and LDL cholesterol were even larger in men than women, and subjects with high cholesterol benefited the most. Studies in which particpants consumed more than 80 mg of soy protein containing isoflavones daily resulted in better effects on the lipid profile (a person's LDL, HDL and triglycerides).
The strongest lowering effects of soy protein containing isoflavones on total cholesterol, LDL cholesterol, and triglycerides occurred within the first few weeks, while improvements in HDL cholesterol were only seen in studies lasting more than 12 weeks.
In contrast, tablets containing extracted soy isoflavones did not produce a significant effect on total cholesterol reduction.