Soy pills cut hot flushes by a fifth, and two reviews disagree
The figure comes from double-blind trials at a median 54 mg of soy isoflavones a day, run for six weeks to twelve months. Two later reviews declined to agree.
What the study found
Soy pills cut hot flushes by a fifth, and two reviews say otherwise
The figure comes from double-blind trials at a median 54 mg of soy isoflavones a day, run for six weeks to twelve months, with severity falling by about a quarter alongside frequency. The Cochrane review and the North American Menopause Society both looked again and declined to agree.
The caveat · Pooled trials contradict each other
Heterogeneity is high, 67 percent for frequency and 86 percent for severity, so the pooled figures sit on trials that contradict one another. The results are percentages, not flushes per day, which flatters a small absolute change. A co-author directs the industry-funded Soy Nutrition Institute.
What we don't know
Whether soy pills ease hot flushes is unsettled because the reviews disagree first about whether trials this varied can be combined at all, and only then about the answer. That is why more studies have not settled it.