That finding comes from a new study of 1,651 women. Researchers from the University of California, Davis, (UC Davis) followed the women for 10 years, starting when the women were in their 40s and early 50s.
None had menopause-related hot flashes when they enrolled in the study, but many experienced them over the next decade.
The study showed no evidence that women whose diets contained more soy were less bothered by hot flashes and night sweats than women who ate little soy.
The researchers say very few of the women took soy supplements.
“Typically if something works, even if all the studies don’t show it, the majority will,” she says. “That is not what we have seen in the soy (and hot flash) studies.”
Estrogen, Soy, and Hot Flashes
Asian women who live in countries where soy is a big part of the diet report far fewer hot flashes than women living in Western countries, and one theory has been that their diets protect them.
The new study, which appears in the March issue of the NAMS journal Menopause, included white, African-American, and Asian women in the U.S.
It differed from much of the previous research by excluding women who were already having hot flashes.
“We wanted to see if dietary phytoestrogens could prevent hot flashes in women who were not yet having them,” says researcher Ellen Gold, PhD, a professor and chair of the UC Davis department of public health sciences.
This research is very preliminary, and Gold says even though the soy and hot flash studies are inconclusive, there is little downside to eating soy-rich foods or taking soy supplements.
“Many women cannot or won’t take hormone therapy,” she says. “I don’t see anything wrong with taking soy supplements in reasonable doses. If it gives someone relief, ultimately that is what counts.”