Soy Can't Destroy Hot Flashes

Osteoporosis not helped by soy supplements

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Menopause can be a rough time. Women suffering from hot flashes, bone density loss and night flashes are usually willing to try diet changes to alleviate their symptoms.

According to a recent California study, it doesn't appear symptoms of menopause are able to be reduced by soy supplements.

The Soy Phytoestrogens as Replacement Estrogens (SPARE) trial, was conducted to address the shortcomings of prior trials on soy products. The soy group and the cohort group had virtually identifical results on bone density loss. Hot flashes and night sweats were not better for women in either group.

"Regular exercise during menopause can help reduce symptoms."

Katherine M. Newton, Ph.D., of the Group Health Research Institute, Group Health Cooperative, Seattle, and Deborah Grady, M.D., M.P.H., of the University of California, San Francisco and San Francisco VA Medical Center report that of the women going through menopause, 80 percent will have hot flashes, night sweats and/or bone density loss. Only 20 percent of these women seek treatment for the discomfort, though.

Drs. Grady and Newton both report that most women decline estrogen therapy with or without progesterone now because of the Women's Health Initiative report that the risks of this hormone replacement therapy outweighs the benefits. 

Their study looked at 248 women who experienced comparable menopausal symptoms of night sweats and hot flashes. Study participants were randomized to receive either a 200 mg soy isoflavone supplement or a placebo tablet. During a two year follow-up of these two groups of women, there was no significant difference in bone density loss in the femoral neck, total hip or spine.

At the study's conclusion, participants taking the soy tablet were actually more likely to have hot flash symptoms compared to the women in the placebo group ( 48.4 percent compared to 31.7). Also, the women taking the soy supplement reported a greater incidence of constipation (31.2 percent vs. 20.6 percent).

The study authors recommend that research should target more individually tailored therapies for menopause instead of a "one size fits all" approach. They also concede that it is difficult to verify new therapies for hot flashes and night sweats because little is known regarding the mechanism that triggers these symptoms.

This report is in the August 8 2011 issue of Archives of Internal Medicine.

Reviewed by: 
Review Date: 
August 7, 2011
Last Updated:
August 10, 2011