Hot flashes are a common discomfort associated with menopause. Approximately three-fourths of post-menopausal women experience them, according to the "Mayo Clinic Proceedings." Although the exact mechanism is not fully understood, the drop in estrogen causes mixed signals that your body is too warm. Some women find relief when they add soy products to their diet.
Soy Isoflavones
Soy products are made from soybeans, which are rich in isoflavones. These are also called phytoestrogens because they are plant-based biochemicals with weak estrogen activity. They are capable of binding to estrogen receptors in your body. The amount of isoflavones in soy products varies. According to the U.S. Department of Agriculture Database for the Isoflavone Content of Selected Foods, 100 g of miso has 41.45 mg isoflavones, soy protein drink has 81.65 mg, soy yogurt has 33.13 mg and soy milk has 2.56 mg. A 1-cup serving of soy milk has approximately 35 mg of isoflavones.
Theories
The exact cause of hot flashes during menopause is not entirely understood. But what is known is that the sudden drop in estrogen or even a diminishing drop in estrogen triggers hot flashes. The hypothalamus is the part of the brain that controls heat changes much like a thermostat. With less estrogen, certain things such as hot drinks and stress will cause the hypothalamus to react as if you have become too warm. The brain reacts by dilating blood vessels near the skin's surface to cool off, and perspiration will often result. These hot flashes can be both unpleasant and embarrassing. They can interfere with your sleep when they happen at night.
Research
According to a 2010 study published by the North American Menopause Society, isoflavones were successful in reducing hot flashes and insomnia in post-menopausal women. For four months, one group of women were given a daily dose of 80 mg of isoflavones and a control group were given a placebo. There was a significant increase in sleep efficiency and a reduction in the intensity and amount of hot flashes for the isoflavone group.
Another study in Japan had similar results. For six years 1,106 women, aged 35 to 54 were studied, comparing their soy and isoflavone intake with hot flash occurrences. It was determined that the greater soy intake resulted in fewer hot flashes. The study was published in the "American Journal of Epidemiology."
Considerations
Hot flashes are a normal occurrence during menopause but you should always seek guidance from your medical professional. Allergies to soybeans are rare but possible; talk with your doctor if you have any concerns.
References
- BreastCancer.org: All About Hot Flashes
- Mayo Clinic Proceedings: Pathophysiology and Treatment of Hot Flashes
- USDA Nutrient Data Laboratory:USDA Database for the Isoflavone Content of Selected Foods, Release 2.0
- PubMed: Isoflavones Decrease Insomnia in Postmenopause
- American Journal of Epidemiology: Soy Product Intake and Hot Flashes in Japanese Women: Results from a Community-based Prospective Study
