Q: Is soy safe for women who have had estrogen-related tumors?
– Katie from Wisconsin

A: No one knows for sure. Soy contains estrogen-like compounds called phytoestrogens that have a weak estrogen activity. These phytoestrogens bind to estrogen receptor sites and block a woman’s natural estrogen from entering. Researchers suspect that this is one reason why adding soy to women’s diets lowers their risk for breast cancer. On the other hand, some researchers speculate that adding more estrogen to the body, even if it’s a mild form, could escalate cancer risk in women with a history of breast cancer. There are no definitive studies to prove this. On the contrary, cultures where women regularly consume soy, such as Japan, breast cancer rates are very low. In addition, soy-based infant formulas have been used in the United States for more than 30 years with no indication of long-term problems. The bottom line: I recommend that women with no history of breast cancer include several servings of soy in their weekly diets, and that women with a history of breast cancer consume whole soy foods (tofu and soy milk) in moderate amounts, say two or three servings a week. -Elizabeth Somer