A panel of experts from the American Heart Association questions the benefits of consuming soy-based foods and supplements to reduce cardiovascular risk ... and offers bottom-line advice.
Tofu, soy protein, soymilk, soy flour, soy butter, and edamame (edible green soybeans) are all phytochemicals -- compounds from plant goods that may help to lower the risk of certain diseases. Tofu and other soy products are mild tasting and pick up the flavor of the foods they are cooked with. For example, tofu can be stir-fried with vegetables or added to soups. Soy flour can substitute for up to one quarter of the flour in baking recipes, and soy butter can be spread on bread in place of peanut butter.
Soy-based foods and supplements have been touted as a way to lower cholesterol levels and reduce cardiovascular risk. But a review of 22 randomized trials by a panel convened by the American Heart Association (AHA) does not support earlier evidence that soy protein or the isoflavones it contains produces large benefits on blood lipids or blood pressure. These findings were reported in the journal Circulation (Volume 113, page 1034).
The review found that consumption of soy protein with isoflavones at a high dose of about 50 g a day (about half of the usual daily protein intake) reduced low-density lipoprotein (LDL) cholesterol levels by only about 3% and had no significant effect on high-density lipoprotein (HDL) cholesterol, triglycerides, or blood pressure. In the area of women’s health, soy was not found to lessen hot flashes associated with menopause. Results were mixed on its ability to slow postmenopausal bone loss. And the isoflavones in soy had no proven effect in preventing or treating breast, uterine, or prostate cancer. Based on these results, the AHA panel does not recommend getting isoflavones from food or pills.
However, all is not lost: The panel says soy protein is still a good substitute for animal protein, because soy-containing foods have a high content of vitamins, minerals, fiber, and polyunsaturated fats.
