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Soy Has Potential to Alleviate Menopausal Hot Flashes

Hot flashes brought on by menopause can be a real pain. For a lot of women these frustrating bouts of heat interrupt sleep, causing you to become more irritable and stressed than you already are. Though there are many ways to alleviate more severe symptoms of menopause, like bioidentical hormone replacement therapy, a new study suggests that soy has the potential to alleviate menopausal hot flashes.


Hot flashes occur when blood vessels near the skin’s surface dilate to cool, producing a red flushed look to the skin. Sometimes, hot flashes are accompanied by perspiration, rapid heart rate and chills. Soy contains compounds known as isoflavones that are thought to have weak estrogen-like effects in some body tissues. This led researchers to believe that soy or soy extracts could help cool hot flashes.


The Study

The Journal of the North American Menopause Association published findings that reviewed 19 previous studies making it the most comprehensive study to examine the effects of soy on menopausal hot flashes to date. The study found that two daily servings of soy can reduce the severity and frequency of hot flashes by up to 26 percent when compared to a placebo.


Though previous studies were inconclusive on the effects of soy on hot flashes, this was mostly due to insufficient sample size and inconsistent methodology. However, when the studies were combined researchers found the overall effect of soy on menopausal hot flashes to be positive.


After examining the effects of the isoflavones in soy, researchers found:

Compared to a placebo, ingesting at least 54 milligrams of soy isoflavones each day for six weeks to one full year reduced hot flash frequency by 20.6 percent and hot flash severity by 26 percent.

  • Due to the placebo effect, this frequency and severity reduction might be even greater.
  • Compared to shorter duration trials, when women consumed soy isoflavones for 12 weeks, hot flash frequency reduction was three times greater.
  • Isoflavone supplements with 19 milligrams or more of genistein were more than two times as effective at reducing the frequency of hot flashes.


The Takeaway

Since genistein is the primary isoflavone in soybeans and soy foods, researchers suggest eating soy foods or soybean supplements may work better for women. To put this in perspective, each gram of soy protein in soybeans or soy foods can provide you with approximately 3.5 milligrams of isoflavones. Approximately 16 ounces of soy milk (two glasses) or seven ounces of tofu can provide you with approximately 50 milligrams of isoflavones.


Though more research is still needed to investigate these results, it may be helpful for women suffering from menopausal hot flashes to slowly introduce small amounts of soy into their diet. As always, it’s best to consult with your physician before making any drastic dietary adjustments.