Is soy effective in curing hot flashes?

Even though the jury is still out on soy, some women may find modest hot flash relief, says Margery Gass, MD, executive director of the North American Menopause Society. One study found that women who took a daily 160 mg dose of soy isoflavones -- the active soy ingredient that mimics estrogen -- reported feeling better during menopause, emotionally, physically, and sexually. However, studies have been inconclusive, says Dr. Gass, because "everybody's formulating it differently and using different doses of soy isoflavones, so it's tough to compare across trials." If you don't see an improvement within 12 weeks of adding soy to your diet, it's not worth continuing, she advises. Though soy isoflavones are considered safe for most women, those with a personal history of breast cancer may want to avoid it. Always talk with your doctor before taking any new supplement.

Julia Schlam Edelman
OBGYN (Obstetrics & Gynecology)
No doubt you have read at least one article promoting the role of soy foods and phytoestrogens (plant-derived estrogen-like substances) as a method of handling hot flashes. But there is no definitive data about their effectiveness. Studies about eating soy have produced contradictory findings. Soy foods have been shown to decrease the frequency and severity of hot flashes in some studies, but not others. And there are a few concerns. The safety of soy supplements has not been established. Soy foods are preferable. One concern about soy that has not been resolved is its effect in women who have had breast cancer. At this time, women who have had breast cancer are advised not to take soy supplements. Consuming one or two servings of food that contains soy on a regular basis is not thought to be harmful, but more data is needed. Asian women consume more soy foods than North American women and have a lower rate of breast cancer.

The second area of complexity that may contribute to the contradictory findings about soy is that phytoestrogens possess both estrogen-like properties and anti-estrogen properties. That is to say, in some ways they may act like estrogen, alleviating hot flashes, and in other ways, they may act as estrogen-antagonists and behave exactly opposite to the way estrogen would behave. A caution for all women, regardless of health history: avoid taking soy supplements. Although some women prefer the ease of taking a soy supplement as a pill or tablet, it may be detrimental -- and there is no evidence that it is beneficial. In addition, the additives used to manufacture the supplements may not be healthy. Further, some supplements may contain too much of a particular type of soy, even more than the body can use or eliminate.

Soy supplements are not well studied or understood, but we do know that to make soy supplements, soy must be extracted and processed, which affects the amount of isoflavone that remains in the product. Sometimes, removing the fat or taste or color of natural soy to turn it into a supplement product removes the beneficial isoflavones. If the beneficial isoflavones are removed, the soy supplement may not provide the benefits found in foods such as tofu, soybeans, soymilk or soy cheese, and other types of beans.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.