Placebo alone cut hot flushes by 1 to 59 percent
That spread comes from 43 randomised trials in 4,364 women, and it is wide enough to swallow any treatment effect those trials were built to measure.
What the study found
Placebo alone cut hot flushes by anywhere from 1 to 59 percent
That spread comes from 43 randomised trials in 4,364 women, and it is wide enough to swallow any treatment effect those trials were built to measure. It is the plainest explanation on offer for why studies of soy for hot flushes keep disagreeing with one another.
The caveat · Stronger extracts did reduce flushes
The trials were too dissimilar to combine, so the review's only pooled estimate is of red clover, a different plant. Four trials of extracts delivering more than 30 mg of genistein a day did consistently reduce flushes, so the negative verdict is not uniform across preparations.