Supplements Containing Soy Isoflavones Don't Benefit Arteries

Eating a diet rich in soy can help to keep arteries free of atherosclerosis, however it appears that supplements containing soy isoflavones are of no real benefit. Dr Janice D Wagner of Wake Forest University in North Carolina and colleagues studied 60 monkeys fed an atherogenic - that is an atherosclerosis inducing - diet.  After following the diet for two months, the monkeys were split into three groups for a further 20 weeks, One group got all their protein from soy, another ate only milk protein, while the third ate milk protein plus the isoflavones genistein, daidzein and glycitein. Results showed that soy-fed monkeys had significantly less LDL, or bad, cholesterol in their arteries than monkeys fed either the milk protein diet or the milk protein diet supplemented with isoflavones. There are several possible reasons as to why eating soy protects the heart but consuming soy isoflavones does not: firstly, there is the possibility that isoflavones are not actually responsible for the cardiovascular benefits of soy: secondly, it is feasible that the body metabolizes whole soy and soy ingredients differently.

SOURCE/REFERENCE: Arteriosclerosis, Thrombosis and Vascular Biology 2003;23:2241-2246.