Soy Does Nothing to Ease Symptoms of Menopause

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What is a menopausal woman to do? A new study finds that taking soy supplements, a popular alternative to hormone-replacement therapy, does not help relieve the symptoms of menopause or protect against bone loss.

After two years of taking daily soy isoflavone tablets, women showed no differences in bone density and no improvement in symptoms such as hot flashes or night sweats, compared with women taking a placebo. Indeed, by the end of the study, more women taking soy were having hot flashes than women taking placebos.

Soy has been considered a potentially safer alternative to hormone therapy because of its isoflavones, or plant-based estrogens. Researchers have also observed that women in Asia, whose diets are typically rich in soy, are less likely to have bone loss, osteoporosis and cardiovascular disease than their Western counterparts. To date, however, most clinical trials of soy have been limited by their small size, short duration or faulty design. The aim of the current study was, therefore, to offer a more definitive conclusion.

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Researchers led by Dr. Silvina Levis, director of the Osteoporosis Center at the University of Miami Miller School of Medicine, randomly assigned 248 women to take either 200 mg of soy isoflavones — a dose that is roughly twice the amount of dietary soy isoflavones found in a typical Asian diet — or placebo tablets for two years. Neither the researchers nor the women knew who was taking which pills until the end of the study.

The women were 45 to 60 years old at enrollment, and all were within five years of the start of menopause.

Researchers used bone scans to measure women’s bone mineral density at the hip and spine. At the end of the study, the scans showed no differences between the soy and placebo groups. Both groups had small amounts of bone loss.

Researchers also used questionnaires to gauge the frequency of women’s menopausal symptoms. At the start of the study, 176 women reported at least one symptom. The most common ones: hot flashes (50%), night sweats (38%), insomnia (37%), loss of libido (37%) and vaginal dryness (31%).

At the end of the two-year intervention, the two groups showed no differences in symptom improvement. In fact, the frequency of hot flashes didn’t change in the soy group, but decreased in the placebo group, so that more women taking soy (48%) ended up with hot flashes than those taking placebo (32%). Women in the soy group were also more likely to have constipation and bloating.

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“When we started the study we wanted this to work, because it would provide an easy and healthy way to help women in the initial stages of menopause,” Levis told Reuters.

Seeing as how it didn’t, what other alternatives to hormone therapy do women have? For hot flashes, some antidepressants or the anti-seizure medication gabapentin may work. Exercise also helps, and so may deep breathing exercises done regularly. Some women say they have found relief through yoga and acupuncture.

To protect against bone loss, women should make sure to get enough calcium and vitamin D, get regular weight-bearing exercise and refrain from smoking or overindulging in alcohol. Taking bisphosphonates can also help maintain bone mass.

So far, efforts to develop alternative menopause therapies as effective as hormone replacement have come up short, notes Dr. Deborah Grady, a professor of medicine at the University of California, San Francisco, in an invited commentary accompanying the study in the Archives of Internal Medicine.

“The important question for women is what degree of symptom relief is sufficient,” Grady and co-author Katherine Newton, an epidemiologist at the University of Washington Seattle, write. “Perhaps efforts should be directed away from the hope of a one-size-fits-all therapy for menopausal symptoms toward using existing treatments to target the symptoms that disturb patients most.”

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