In good news for menopausal women, a new, large-scale review found that two daily servings of soy can reduce the frequency and severity of hot flashes by up to 26 percent, compared to a placebo.
The findings, published in Menopause: The Journal of the North American Menopause Association, reviewed 19 previous studies that examined more than 1,200 women.
Among the results:
• Ingesting at least 54 milligrams of soy isoflavones daily for six weeks to a year reduces menopause hot flash frequency by 20.6 percent and severity by 26 percent, compared to a placebo.
• The total reduction in frequency and severity might be even greater due to the placebo effect.
• In longer duration studies (where women consumed soy isoflavones for 12 weeks or more), the decrease in hot flash frequency was approximately threefold greater than in shorter-duration trials.
• Isoflavone supplements with higher levels (at least 19 milligrams) of genistein, one of the two main types of isoflavones, were more than twice as effective at reducing hot flash frequency than lower amounts.