Can Soy Fight Hot Flashes? New Study Says it Depends on Genes

Updated: Oct 14, 2020

Researchers found that some women are genetically predisposed to find soy more effective against hot flashes than others.
General Information
  • 01 May 2015
  • USA
  • The North American Menopause Society
  • Newton, K.M. et al.
  • Observational study
  • 365 women
  • 4 days

The results of a recent study published in Menopause: The Journal of The North American Menopause Society (2015) suggest that soy can be useful for reducing the frequency of hot flashes, but only in women who produce the necessary soy metabolite, equol.

The Study

The participants were all between the ages of 45 and 55, none were using hormone replacement therapy (HRT), and all of them ate soy foods at least three times a week. The results were based on reports from the women themselves, who recorded how many hot flashes they had and also how severe they were. The hot flashes were measured with a skin monitor, and urine tests were also required in order to determine which women produced equol, which is a metabolite generated by gut bacteria during the digestion of soy.

The Results

As it turns out, 35% of the women produced equol, and among these women, more soy consumed meant fewer hot flashes. The statistic was staggering: 76% less likely to experience hot flashes higher than the average number women experience. Among women who did not produce equol, soy made no difference in their menopause symptoms.

What Does This Mean?

As the urine test for equol is exclusively conducted in research facilities, there is no way for a woman to know if she is an equol-producer, so she will not be able to predict whether or not soy will reduce her hot flashes. The North American Menopause Society recommends women to experiment by incorporating soy into their diet for a few weeks to see if it makes any difference. If soy supplements prove ineffective, however, there is still the option of using other hormone-balancing herbal supplements with similar actions - such as maca or vitex chasteberry - or taking an equol supplement, always under professional medical advice.


  • Menopause, A cross-sectional study of equol producer status and self-reported vasomotor symptoms, 2015