Researchers from the Medical University of Vienna reviewed and reanalyzed the results from 25 studies of the treatment of the climacteric syndrome (menopause).

Their findings are not always clear-cut.

Vasomotor symptoms

  • Individual studies reported significant reductions in vasomotor symptoms (hot flashes, night sweats) for red clover and soy phytoestrogens.
  • However, after combining and re-evaluating the results (meta-analysis) of several studies, there was no significant reduction of vasomotor symptoms for phytoestrogens.

Women with early natural postmenopause

  • A significant reduction of hot flashes reported in 5 out of 5 studies.

Breast cancer

  • A reanalysis of the results from 21 studies revealed a significantly reduced incidence of breast cancer among past phytoestrogen users.
  • But individual well-designed studies did not show protection from breast cancer.

This might sound contradictory, but I think it’s because the results of studies that looked at past history could not be confirmed by studies specifically designed to look for a protective effect going forward.

Other effects

  • Phytoestrogens have a positive effect on bone, blood vessels; platelet aggregation (important for clotting); insulin resistance; and blood levels of triglycerides, LDL (bad) cholesterol, and HDL (good) cholesterol.
  • None of the available studies documented a protective effect of phytoestrogens for bone fracture or cardiovascular events (heart attack, angina, stroke).

The bottom line?
The reviewers believe that phytoestrogens might have value in selected women — those presenting with mild to moderate vasomotor symptoms in early natural postmenopause.

It appears that “None of the compounds investigated so far have been proven to protect against breast cancer, bone fracture, or cardiovascular disease.”

5/11/07 21:15 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.