On the heels of National Soy Food Month, I would like to follow up on my last discussion about soy with a focus on women. It can be difficult to keep up with the facts when soy is recommended to fight hot flashes one day and is decried as causing cancer the next. Let’s look at some common questions about soy:
Is soy nutritious?
Whole soy foods, including soy beans, edamame, tofu, tempeh, and soy milk, contain a variety of phytochemicals and antioxidants that work to protect against heart disease, some cancers, and type 2 diabetes. Soy is also high in protein and fiber, has a variety of both vitamins and minerals, contains healthy fats, and is relatively low in calories.
Does soy cause breast cancer?
Natural soy foods contain isoflavones, which are similar to estrogen; thus my clients often think soy will raise their risk for hormone-sensitive cancer, such as breast cancer. Studies exploring the relationship between soy intake and breast cancer have been mixed, but recent research suggests soy does not promote the development or progression of breast cancer. According to the American Institute for Cancer Research, consumption of soy among breast cancer survivors, at levels of 1 to 2 serving per day, did not increase their risk for poorer outcomes.
Is soy good or bad for the heart?
Research on soy and heart health is promising. There is evidence that soy lowers LDL (bad) cholesterol slightly, and soy’s fiber and antioxidants are heart-healthy. Consider a soy-based meal once a week in place of meat, but use caution with meat alternatives such as soy crumbles, burgers, or sausage, as these often have a lot of added salt.
Can soy prevent hot flashes and other symptoms that occur after menopause?
Because soybeans have isoflavones, it seems logical they would relieve symptoms caused by low levels of estrogen in the body. Thus, soy has been studied as a treatment for hot flashes, with inconclusive results. While some research found fewer hot flashes and night sweats in women who consumed soy, others found equal results with a placebo. While the jury is still out, I advise against soy supplements or overconsumption, but instead recommend a moderate intake for its other health benefits.
Melissa Wdowik, PhD, RDN, is an assistant professor at Colorado State University in the Department of Food Science and Human Nutrition, and director of the Kendall Reagan Nutrition Center.