Soy tablets do little to stave off bone loss among menopausal women, according to new research. Women taking soy supplements also reported more hot flashes andconstipation.
After the landmark Women’s Health Initiative showed that hormone replacement therapy carried health risks, many women gravitated toward soy products as a safer alternative because soy is rich in isoflavones, so-called “dietary estrogens.” Western women were also encouraged by studies that showed that their Asian counterparts, who eat a soy-rich diet, have lower rates of bone fractures, breast cancer andcardiovascular disease.
In this new study, researchers conducted a clinical trial in South Florida between July 2004 and March 2009 to assess whether taking soy supplements delayed bone loss associated with menopause. Nobody – not the subjects, not the scientists – knew who was getting the soy and who was getting a placebo. Women in the trial, 248 in number, were between the ages of 45 and 60, had gone through menopause in the last five years and had hip or lower back bone mineral density T-scores less than -2.0.
(The T-score is a measure of how thick your bones are relative to the average 30-year-old. A negative number means thinner bones. Having a score lower than -2.5 is considered a sign ofosteoporosis. For more about bone density, check out this information at the Mayo Clinic website.)
Women in the soy group received 200 mg of soy isoflavones – about twice as the highest daily intake in a typical Asian diet – which they were instructed to take daily before breakfast. Participants who got less than 500 mg of calcium each day were also given calcium supplements.
After two years, the researchers measured bone density in the women’s lower back, hips and hip joints. The women also had to fill out surveys about menopausal symptoms such as hot flashes.
In all, 99 women in the soy group and 83 women taking a placebo completed the study.
Here is a summary of what the researchers reported in their study, which was published in the Archives of Internal Medicine:
- Bone density in the lower back, hips and hip joints wasn’t higher in women taking soy supplements. The researchers only noticed less bone loss in the soy group among women who had vitamin D levels lower than 20 ng/mL.
- For the most part, both groups had similar menopausal symptoms. The only difference was in hot flashes. By the end of the study, almost 50% of women taking soy tablets said they had hot flashes, compared to 32% of women in the placebo group. That’s MORE hot flashes in the soy group.
- More women taking soy supplements also complained of being constipated.
- Cholesterol was not affected by taking soy supplements.
- Seven women taking soy supplements had a bone fracture, compared to just one in the placebo group, but all were the result of an injury and not osteoporosis.
So what lifestyle measures CAN you take to protect your bones after menopause? You’ll find a variety of bone-building tips at a website for the Department of Health and Human Services, which recommends, among other things: getting enough calcium and vitamin D, plenty of weight-bearing physical activity (walking, dancing, running, climbing stairs, jogging, gardening, more), not smoking, and minimizing alcohol so as to (a) not interfere with calcium absorption and (b) not mess up your balance.
Oh, and it’s also recommended that you make your house safe so you’re less likely to fall. Watch out for those slippery rugs.