The Study
Isoflavones and changes in body weight and severe hot flashes in postmenopausal women: A secondary analysis of a randomized clinical trial
This study gave some women a special diet with lots of soy and others kept eating normally, then saw what happened. It found that women who ate soy had fewer hot flashes and lost weight, and it looks like one part of soy (daidzein) might be why. But we can't be 100% sure it was the soy alone — maybe other parts of the diet helped too.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Women who ate soybeans every day on a low-fat vegan diet had way fewer hot flashes, even though they also lost weight.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 562 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This means eating soybeans might directly help stop severe hot flashes, even if you don't lose weight.
- 2Hot flashes dropped from 1.3 per day to 0.1 per day.
- 3Daidzein (a soy compound) was linked to this drop.
- 4Weight loss didn't cause the drop.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Maturitas
Year
2025
Authors
Hana Kahleova, Tatiana Znayenko-Miller, Richard Holubkov, Neal D. Barnard
Related Content
Claims (6)
Postmenopausal women who eat 86 grams of cooked whole soybeans daily as part of a low-fat plant-based diet experience a 79% reduction in total hot flashes and an 84% reduction in moderate-to-severe hot flashes after 12 weeks.
Postmenopausal women who ate 86 grams of cooked whole soybeans daily as part of a low-fat plant-based diet experienced an 88% reduction in moderate-to-severe hot flashes, while those who did not had a 34% reduction.
Postmenopausal women who consume more daidzein in their diet experience 92% fewer severe hot flashes than those who consume less, after accounting for total calorie intake and body weight changes.
Postmenopausal women who followed a low-fat vegan diet with soybeans for 12 weeks experienced a 92% reduction in severe hot flashes, going from 1.3 per day to 0.1 per day, while women in a control group showed no change.
Higher consumption of daidzein, genistein, and glycitein from soy is linked to a decrease in body weight among postmenopausal women.
In postmenopausal women, losing weight on a low-fat vegan diet with soybeans does not correlate with a decrease in severe hot flashes, suggesting the two changes occur independently.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.