The hormone replacement therapy has a beneficial effect on bone mineral density but increases the risk for certain cancers. The Journal of the American Medical Association revealed in the July 17, 2002 edition, the results of a study. They followed 16,608 women for an average of 5 years. In this study, they found that using hormone replacement therapy increased the risk of breast cancer by 26 percent, stroke by 41 percent and pulmonary embolism by more then 100 percent.
Isoflavone phytoestrogen therapy has been proposed as a natural alternative to hormone replacement therapy. The objective of the study was to determine the effect on bone density of a red clover isoflavone supplement.
Women aged between 49 and 65 year were enrolled in a double-blind, randomized, placebo-controlled trial. They were given daily isoflavones supplements containing 26 mg biochanin A, 16 mg formononetin, 1 mg genistein, and 0.5 mg daidzein for 1 year. The bone mineral density, body composition, bone turnover markers were measured at start and after 12 months. The loss of lumbar spine bone mineral content and bone mineral density was significantly lower, and bone formation markers were significantly higher in the women taking the isoflavone supplement than in those taking the placebo. There were no significant effects on hip bone mineral content or bone mineral density, markers of bone resorption, or body composition.
It can be concluded that isoflavones have a potentially protective effect on the lumbar spine in women.
Source: Atkinson C, Compston JE, Day NE, Dowsett M and Bingham SA. The effects of phytoestrogen isoflavones on bone mineral density in women: a double-blind, randomized, placebo-controlled trial. American Journal of Clinincal Nutrition, 2004 Feb;79(2):326-33