Are Hot Flashes the Bane of Your Existence?

Many women are all too familiar with hot flashes… the sudden feeling of warmth in the upper body that is especially intense on the face, neck and chest; the reddened skin; the sweating.  If they happen at night they are called night sweats and are a huge sleep disrupter.  Most hot flashes occur during menopause, the time of life when menstrual periods become intermittent and eventually disappear.  They may be mild or intense and can happen at any time, day or night.  A single hot flash can last from a minute or two up to five minutes and leaves behind a distinct feeling of clammy chilliness.  Although their occurrence is variable, most women who suffer from hot flashes have them daily and they can persist for many years, sometimes as many as ten.  (1)  In Western countries, up to 80% of menopausal women experience hot flashes (2).

Happily, good news about hot flashes is building up.  In 2021, the North American Menopause Society published a study that looked at the effects of a diet rich in soy on hot flashes.  This study, called the WAVS trial, included 38 post-menopausal women reporting two or more hot flashes a day.  The participants were randomly assigned to one of two groups (2);

  1. A low-fat, vegan (plant-based) diet that included ½ cup of cooked soybeans added to a soup or salad daily
  1. A control group that simply continued eating their regular diet for 12 weeks.

The results of this trial revealed the following (2);

  • Moderate-to-severe-hot flashes decreased by 84% (from nearly five hot flashes per day to fewer than one per day) in the group eating the plant-based diet enriched in soy, significantly more than the 42% decrease observed in the control group.
  • 59% of the women eating the plant-based soy-rich diet became totally free of moderate-to-severe hot flashes over the 12-week study period while none of the women in the control group became hot flash-free
  • Hot flashes, from mild to severe, among the whole group of women eating the plant-based soy-rich diet decreased by 79%
  • The women eating the plant-based soy-rich diet reported significantly greater reductions in the severity of their hot flashes and improved quality of life.

This study strengthened observations from previous randomized trials illustrating that soy products showed promise in reducing the frequency of hot flashes.  Indeed, hot flashes occurred much less frequently in Asian countries whose traditional diets emphasized plant-based foods such as rice, vegetables and soy products.  In the 1980s, as the diet in Japan became westernized, reports of hot flashes doubled.  (2)

Research suggests that it is the isoflavones in soy products, nonsteroidal phyto-estrogens (genistein, daidzein and glycitein), that are exerting this inhibiting effect on hot flashes. Daidzein can be metabolized by the gut bacterial into equol, a compound that binds to estrogen receptors and lowers the effects of estrogen on the body.  In Japan the ingestion of various soy foods is high at 40 to 100 mg per day and 50 to 60% of Asian adults produce equol compared with only 20 to 30% of Western adults.  Plant-based diets support a healthier bacterial population in the gut and studies have found that people eating mostly vegetarian diets produce equol more frequently than those eating a standard Western diet. (2,3)

In 2022 a new study strengthened the idea of tackling hot flashes with diet.  This time 84 women reporting at least two moderate-to-severe hot flashes daily were again randomly assigned to one of two groups (2);

  1. A low-fat, vegan diet with ½ cup of cooked soybeans daily added to soup or salad
  2. A control diet that made no dietary changes. The trials lasted for 12 weeks.

Results of this study illustrated the following (4);

  • Moderate-to-severe hot flashes decreased in the intervention group by 88% compared with a 34% reduction in the control group.
  • At 12 weeks, 50% of the participants in the intervention group exhibited no moderate-to-severe hot flashes at all. The control group showed no change in hot flash frequency.



Transforming These Study Results into An Action Plan to Stop Hot Flashes

  • Transition to a completely plant-based diet that includes vegetables, fruits, legumes (beans, peas, lentils) and whole grains.
  • Completely avoid animal-sourced food (meat, poultry, fish, dairy products and eggs)
  • Eat ½ cup of cooked soybeans every day. Canned soybeans can be eaten or the beans can be prepared from their dried form.  Eat them added to dishes such as soups, stews or salads; or lightly season with a bit of salt, garlic powder or chili powder and roast to enjoy them as a snack.
  • Limit fat intake by…
    1. Avoiding the use of oils when cooking. Use other liquids such as apple juice, wine or vegetable stock.
    2. Avoiding processed foods that contain more than 3 grams of fat per serving.
    3. Reducing consumption of plant foods that are higher in fat such as avocados, olives, coconut, nuts and seeds.




2  Barnard, N.D., Kahleova, H., Holtz, D.N., Del Aguila, F., Neola, M., Crosby, L.M., Holubkov, R.  The Women’s Study for the Alleviation of Vasomotor Symptoms (WAVS): a randomized, controlled trial of a plant-based diet and whole soybeans for postmenopausal women. Menopause (New York, N.Y.). 2021; 28(10): 1150–1156.

3 Watanabe, S., Uehara, M. Health Effects and Safety of Soy and Isoflavones.   Chapter 22 from the book, “The Role of Functional Food Security in Global Health”, Pages 379-394.  Published by Academic Press, 2019. ISBN 9780128131480.

4  Barnard, N.D., Kahleova, H., Holtz, D.N., Znayenko-Miller, T., Sutton, M., Holubkov, R., Zhao, X., Galandi, S., Setchell, K.D.R. A dietary intervention for vasomotor symptoms of menopause: a randomized, controlled trial. Menopause. 2022 Oct 18. Doi: 10.1097/GME.0000000000002080. Epub ahead of print. PMID: 36253903.

Promoting a healthy adventurous lifestyle powered by plants and the strength of scientific evidence.

My name is Debra Harley (BScPhm) and I welcome you to my retirement project, this website. Over the course of a life many lessons are learned, altering deeply-rooted ideas and creating new passions.


  1. Ruth Russell on March 3, 2023 at 10:28 am

    Thanks Deb. This is good info. My night hot flashes have mostly gone now. I may get one after an evening of dinning with a glass of wine. As long as I deal with it right away ( by removing my blankets for a few minutes) it goes away and doesn’t come back.

    • Deb on March 23, 2023 at 4:49 pm

      That’s good to hear, Ruth. Hot flashes can be very difficult if they occur too often and last too long.

Leave a Comment