The women eating a vegan diet also lost an average of 8 pounds, while a control group (who didn’t change their omnivorous habits) lost only about half a pound.
The study highlights how a plant-based diet rich in soy may benefit both hot flashes and weight management, regardless of the level of food processing, says Stephanie Faubion, MD, the medical director for the Menopause Society and an internal medicine doctor at Mayo Clinic in Jacksonville, Florida. Dr. Faubion was not involved in the new analysis.
“Given these and the other known benefits in terms of lowering heart disease and cancer risk, women in midlife should consider leaning into a plant-based diet,” says Faubion.
Do Highly Processed Plant-Based Foods Still Provide Health Benefits?
But that study didn’t look at the quality of the diet in terms of whole foods versus ultra-processed ones. Ultra-processed foods are often high in added sugars, unhealthy fats, and sodium, and low in fiber and other essential nutrients. There’s evidence that, compared with whole or minimally processed foods, ultra-processed foods typically lead people to eat more calories and gain weight.
For the new study, researchers dug deeper into the data from the original study to find out more about what was behind the reduction in hot flash severity. Was it only the absence of meat and animal products that made the difference? Or could the level of food processing also be involved?
In the original study, 84 postmenopausal women who experienced at least two daily moderate to severe hot flashes were randomly assigned either to a low-fat vegan diet with half a cup of cooked soybeans per day, or to a control group that kept eating their usual omnivorous diet.
Women who followed a vegan diet ate a range of foods, for example:
- Breakfast Cinnamon apple oatmeal, breakfast burritos, and blueberry muesli
- Lunch Black bean sweet potato chili, lentil and veggie salad
- Snack Chopped raw veggies and hummus, fresh fruit
- Dinner Pita pizza and side salad, barbecue-style portobello mushrooms, and hearty chili mac and cheese
Cutting out meat and animal products slashed the number of severe and moderate hot flashes by about 90 percent, from an average of five per day to less than one. The control group, made up of women who continued to eat their normal diet that included meat and dairy, had only a 34 percent drop in their hot flashes.
When researchers dug deeper, they found that plant-based ultra-processed foods such as packaged vegan meats, frozen veggie pizza, or plant-based snack bars didn’t show any negative effect on weight or hot flashes in this trial — they had the same positive effects as less processed or whole plant-based foods.
In other words, what mattered most for weight loss and hot flash reduction was whether the foods eaten were animal- or plant-based, not the level of processing.
Effect of a Plant-Based Diet Was Greater Than Anticipated
The improvements in hot flashes in the vegan and soybean group surpassed expectations, says the lead study author, Hana Kahleova, MD, PhD, an endocrinologist.
These are the kind of hot flashes that are impossible to ignore — they wake you up at night or interrupt your important meeting, says Dr. Kahleova, who serves as the director of clinical research at the Physicians Committee for Responsible Medicine, a nonprofit dedicated to saving and improving human and animal lives through plant-based diets.
“Hot flashes have also been associated with an increased risk of cardiovascular disease and diabetes. So this significant reduction not only increases quality of life, but overall health,” she says.
Why a Vegan Diet May Reduce Hot Flashes
Because the women in the vegan and soybean group lost weight, it’s hard to know for certain what led to the benefits — the vegan diet, the addition of soybeans, the weight loss, or a combination of all three — says Faubion.
“It is well-known that weight loss is helpful for hot flash management,” she says.
But Khaleova believes the power of a vegan diet to improve hot flashes goes beyond weight loss. “The fiber in plants feeds our gut microbiome and produces significant metabolic changes. In addition, the isoflavones contained in soy help reduce hot flashes,” she says. Isoflavones have estrogen-like properties.
“A vegan diet also reduces the intake of advanced glycation end-products (AGEs), which is the metabolic trash that builds up in our body as we age and has been associated with hot flashes. Plants have much less AGEs than animal products, which helps the body reset,” says Kahleova.
Should You Try a Plant-Based Diet if You Have Hot Flashes?
Kahleova recommends that women who are struggling with hot flashes consider making dietary changes. “Eat plants, keep the fat intake low, and include soybeans for extra benefits,” she says.
Adams agrees that a plant-based diet is less inflammatory than the standard American diet and tends to decrease a person’s risk of chronic illness. “But I would hesitate to promise women struggling with hot flashes that their symptoms will improve solely on the basis of diet alone,” she says.
Faubion says the research is too limited at this point to suggest any particular hot-flash diet. “At this time, there is stronger evidence for weight loss being helpful for hot flash management than any particular dietary component,” she says.
But she notes that a plant-based style of eating offers numerous benefits beyond whatever impact it may have on hot flashes. “A plant-based diet is considered healthy for many reasons, including reduction of cardiovascular disease and cancer risk. That, coupled with weight loss, can certainly be beneficial for many midlife women,” she says.
