For a phenomenon that affects roughly 75 percent of menopausal American women, hot flashes are still surprisingly mysterious, with little known about how they work or what to do about them.
“We don’t have exact answers — just several theories and questions,” said Dr. Arianna Sholes-Douglas, an obstetrician-gynecologist and author of “The Menopause Myth: What Your Mother, Doctor and Friends Haven’t Shared About Life After 35.” With the decline in estrogen during the menopause transition, the body’s internal thermostat sometimes registers the body as hotter than it is and sets off rapid sweating and a dilation of blood vessels in an attempt to cool down.
But what triggers that process and why? It’s unclear. How are hot flashes connected with other health issues, like cognitive concerns and cardiovascular disease? Also hazy. Treatment options are limited to hormones and just one non-hormonal drug approved by the Food and Drug Administration. All of which, Dr. Sholes-Douglas added, is a clear reflection of the scant attention and little funding devoted to medical research into this phase of a woman’s life.
In the last two decades, researchers have started to investigate another potential source of relief: diet. The idea stems from studies that have found that hot flashes differ across cultures and might be a largely Western experience. With that in mind, researchers have hypothesized that environmental factors, like diet, might play a part in this difference.
But many of the studies on dietary interventions are small or inconclusive, said Dr. Stephanie Faubion, medical director for the North American Menopause Society and a director of the Mayo Clinic Center for Women’s Health. In studies that have suggested certain foods reduce hot flashes, the mechanisms at work are not fully understood, she added.
Still, there is no harm in adjusting your diet to see if it might help manage your hot flashes, Dr. Faubion said.
Which foods might help?
Soy products, like tofu and soybeans, contain isoflavones, which are chemicals that can bind to estrogen receptors in the body, said Neal Barnard, an adjunct professor of medicine at the George Washington School of Medicine. For that reason, the thinking goes, soy may mimic estrogen. It’s one of the most-studied foods in connection to menopausal symptoms, and there’s some evidence that eating it might be associated with fewer hot flashes. But it’s unclear whether that’s because of the soy itself or another mechanism.
In a pair of recent studies, Dr. Barnard and his team randomly assigned 84 postmenopausal women who reported moderate to severe hot flashes to either their regular diets or a low-fat vegan diet rich in whole grains, fruits and vegetables, including a daily half-cup of cooked soybeans. Moderate to severe hot flashes decreased by roughly 80 percent in both studies.
“The caveat there is that this was essentially two different interventions — they were on a whole-food, plant-based diet and they had high soy,” said Dr. Faubion. “So what part of that was responsible for those results? We have no idea.” The women in the study also ended up losing weight, which Dr. Faubion said is noteworthy because some studies have shown a correlation between increased body fat and hot flashes, particularly during certain stages of menopause.
Also of interest to researchers are omega-3 fatty acids. But while some studies have found that taking omega-3 supplements seems to reduce the frequency of hot flashes, others found that they make no difference. Supplements aside, the Mediterranean diet, which is rich in foods containing omega-3s — like flaxseeds, walnuts and fatty fish like salmon — has been shown in some studies to be associated with fewer hot flashes and other menopause symptoms.
Are there foods to avoid?
There’s some evidence that a diet high in sugar and fat is associated with worse hot flashes. Beyond that, doctors often suggest avoiding certain foods and drinks that seemingly trigger a hot flash, said Dr. Hoosna Haque, an OB-GYN at Columbia University Irving Medical Center, such as “spicy food, caffeine, alcohol and also really high-concentrated sugary foods and highly processed foods.”
But, she said, that recommendation is often based just on anecdotal evidence, and it’s not fully understood why those foods and drinks might trigger a hot flash.
“It might just be because they can cause spikes and drops in energy levels,” Dr. Haque said. Or because something like caffeine can dilate blood vessels — much like hot flashes do — and may set off a similar chain of events.
Ultimately, “we counsel patients that a balanced, healthy diet may help relieve symptoms, but it isn’t a treatment,” Dr. Haque said. And healthy diets “can also have beneficial effects down the line, when it comes to things like bone health, weight gain and cardiovascular health.”