The transition into menopause is accompanied by a number of symptoms that can cause significant discomfort for many women. These symptoms include hot flashes, night sweats, insomnia, and irritability. In addition, bone mineral density loss is accelerated during menopause and can lead to the development of osteoporosis and bone fractures. Symptomatic relief can be obtained with the use of estrogen supplementation. Unfortunately, estrogen use has been linked to an increased risk of a number of health risks that include venous thromboembolism, stroke, cognitive impairment, coronary artery disease, breast and uterine cancer. As a result, many women have sought alternative treatment options for the symptomatic relief of the changes that accompany menopause. Soy isoflavones have been thought to be a safer alternative to estrogen because the phytoestrogen content binds to the estrogen receptor and anecdotally provides the benefits without the negative consequences. Researchers lead by Dr. Silvina Levis have found that soy supplementation does not alleviate the symptoms of menopause or aide in bone density preservation. The results of their study were published online in the journal Archives of Internal Medicine. The researchers performed a randomized, placebo-controlled, double blind clinical trial comparing daily soy isoflavone tablets to placebo. The investigators studied the effects on menopausal symptoms and prevention of bone loss. There were 248 women aged 45 to 60 years of age enrolled in the study and they were followed for a period of 2 years. The researchers found no difference between the study participants receiving soy supplementation and those receiving placebo with respect to bone mineral density or menopausal symptom relief. The authors wrote, “Because of concerns regarding the risk of estrogens, a need exists for alternative interventions that could provide the beneficial effects of estrogens in bone and menopausal symptoms without the adverse effects on breast and cardiovascular health. We found that our population of women in the first 5 years of menopause, on average, had low rates of bone loss, and that 200 mg of soy isoflavone tablets taken once daily does not prevent bone loss or reduce bone turnover or menopausal symptoms”. Unfortunately, the results of this study do not provide evidence for the efficacy of soy isoflavones in the treatment of menopausal bone density loss or symptoms. The investigation for alternatives to estrogen will need to continue.
Silvina Levis et al. “Soy Isoflavones in the Prevention of Menopausal Bone Loss and Menopausal Symptoms: A Randomized, Double-blind Trial” Arch Intern Med. 2011;171(15):1363-1369. doi:10.1001/archinternmed.2011.330