Phytoestrogens for Bone Health
Republished with permission of Natural Standards Research Collaboration ©2007


Genistein, a phytoestrogen isoflavone found in soy products, may help increase bone health by reducing bone loss in osteopenic postmeneopausal women. Osteopenic patients suffer from osteopenia or low bone density.

Researchers from the University of Messina in Italy assessed the effects of genistein on bone metabolism in osteopenic postmenopausal women in a randomized, double-blind, placebo-controlled trial.

The study included 389 postmenopausal women with a bone mineral density (BMD) less than 0.795 grams/centimeter squared at the femoral neck and no significant comorbid conditions.

After a four-week stabilization period during which participants received a low-soy, reduced-fat diet, participants were randomly assigned to receive placebo (191 patients) or 54 milligrams of genistein (198 participants) daily for 24 months. Both the genistein and placebo tablets contained calcium and vitamin D.

The primary outcome was bone mineral density at the anteroposterior lumbar spine and femoral neck at 24 months.

The study found that bone mineral density increased in genistein recipients and decreased in placebo recipients at the anteroposterior lumbar spine and the femoral neck. Genistein statistically significantly decreased urinary excretion of pyridinoline and deoxypyridinoline, increased levels of bone-specific alkaline phosphatase and insulin-like growth factor I and did not change endometrial thickness compared with placebo. More genistein recipients than placebo recipients experienced gastrointestinal side effects (19 percent vs. 8 percent) and discontinued the study.

Study limitations were that the study did not measure fractures and had limited power to evaluate adverse effects. Also, it was unclear what effect(s) genestein had as a monotherapy, as it was used in combination with other supplements, potentially altering its effects.

The study authors concluded that 24 months of treatment with genistein has positive effects on bone mineral density in osteopenic postmenopausal women.

Integrative therapies with strong, good or unclear evidence in the treatment of osteopenia and related conditions include calcium, vitamin D, black tea, boron, copper, creatine, DHEA, gamma linolenic acid, horsetail, physical therapy, red clover, soy, Tai chi, tamarind and vitamin K.

For more information on the therapies listed above and isoflavones, please visit Natural Standard's Herbs & Supplements and Health & Wellness databases.

References:

1) Herbert Marini, MD; Letteria Minutoli, MD; Francesca Polito, PhD; Alessandra Bitto, MD; Domenica Altavilla, PhD; Marco Atteritano, MD; Agostino Gaudio, MD; Susanna Mazzaferro, MD; Alessia Frisina, MD; Nicola Frisina, MD; Carla Lubrano, MD; Michele Bonaiuto, MD; Rosario D'Anna, MD; Maria Letizia Cannata, MD; Francesco Corrado, MD; Elena Bianca Adamo, MD; Steven Wilson, PhD; and Francesco Squadrito, MD Effects of the phytoestrogen genistein on bone metabolism in osteopenic postmenopausal women: a randomized trial. Ann. Intern. Med. 2007 Jun 19;146(12):839-47. Summary for patients in: Ann Intern Med. 2007 Jun 19;146(12):I34.

Copyright © 2007 Natural Standard Research Collaboration: The Authority on Integrative Medicine

This article appeared in the August 2007 issue of the Integrative Medicine Newsletter for Natural Standard