Researchers at Wake Forest University Baptist Medical Center in Winston-Salem, N.C., say soy high in plant estrogens called isoflavones significantly lowers cholesterol. Study participants were fed a soy-protein diet that contained one of four amounts of isoflavones, ranging from 3 milligrams to a high level of 62 mg. The most dramatic results during the nine-week study were for those consuming the 62 mg. isoflavone diet. How the isoflavones work is another question. There is some evidence that they need the soy protein to work since other research has shown that isoflavones alone do not lower cholesterol.
Asian women are also less likely than Western women to suffer menopausal hot flashes.
A study in the January Obstetrics and Gynecology suggests phytoestrogens might take the credit for that too. Now there's further evidence to support its role in warding off heart disease. Participants mixed the soy powder into milk or juice or added it to yogurt, cereal or other foods. Unlike estrogen replacement therapy, soy protein did not appear to raise blood levels of the fats known as triglycerides. High triglyceride levels are a risk factor for heart disease.