soy and isoflavone supplements

Many women are asking about soy and isoflavone supplements.

Soy is showing up in lots of foods, shakes, bars, etc.

Isoflavones from soy and other plants are included in many supplements...Promensil, Novasoy, Healthy Woman, etc.

These isoflavones have estrogenic effects and might be useful for several conditions.

Cholesterol. Soy can lower cholesterol about 10%...possibly reducing the risk of heart disease.

Advise people they need to consume at least 25 g/day of soy protein to get this benefit. This works out to be 2 to 4 servings a day of soy milk, tofu, soy-fortified foods, etc.

Tell them not to rely on isoflavone supplements...they may not work as well as soy to lower cholesterol.

Osteoporosis. Soy might increase bone density...and therefore help reduce the risk of osteoporosis. Advise women they can try 40 g/day of soy protein that contains about 80 mg/day of isoflavones.

Hot flashes. Soy sometimes helps with mild hot flashes...but it's not nearly as effective as estrogen. Advise women to try 20-60 g/day of soy protein...or 40-80 mg/day of isoflavones.

Breast cancer. No answer yet...there's evidence that soy and isoflavones can be either protective or harmful.

Soy isoflavones are weak estrogens. In some situations they might help...by blocking the effect of more potent estrogens.

But there are concerns that isoflavones might stimulate breast cell growth...especially in women who already have breast cancer.

Tell women that moderate use of soy FOODS is probably okay.

But caution women with a history of breast cancer to avoid isoflavone supplements or excessive amounts of soy food.

• Other: Soy and Isoflavone Supplements