Soy isoflavones in the management of postmenopausal osteoporosis

Abstract

This is a review article designed to address the effects of soy isoflavones on bone metabolism in postmenopausal women and their place in the prevention and treatment of postmenopausal osteoporosis. Soy isoflavones are natural products that could be used as an alternative to menopausal hormone therapy because they are structurally and functionally related to 17beta-estradiol. In vitro and animal studies have shown that they act in multiple ways to exert their bone-supporting effects. They act on both osteoblasts and osteoclasts through genomic and nongenomic pathways. Epidemiological studies and clinical trials suggest that soy isoflavones have beneficial effects on bone mineral density, bone turnover markers, and bone mechanical strength in postmenopausal women. However, there are conflicting results related to differences in study design, estrogen status of the body, metabolism of isoflavones among individuals, and other dietary factors. The long-term safety of soy isoflavone supplements remains to be demonstrated.

Isoflavones: Chemistry, Analysis, Functions and Effects on Health and Cancer

“…Through stimulating bone formation and inhibiting bone reabsorption, isoflavones can maintain bone health. Human studies including observational and clinical trial studies also support favorable effects of isoflavones showing the results such as increasing bone mineral density and bone mechanical strength, and inhibiting bone turnover in postmenopausal women (Atmaca et al, 2008). Ingestion of isoflavones (more than 90 mg/day of isoflavones) at least 6 months have a significant effect for increasing spine bone mineral density in meta-analyses for randomized controlled trials however the effects on hip and leg bones are controversial (Taku et al, 2010).…”

Factors Affecting Isoflavone Content in Soybean Seeds Grown in Thailand

“…Epidemiological and clinical studies of postmenopausal women have suggested that isoflavones decrease their risk of osteoporosis and cardiovascular diseases while alleviating vasomotor symptoms [4][5][6][7][8]. However, the beneficial effects of isoflavones remain controversial.…”

Effect of soy isoflavones on breast cancer recurrence and death for patients receiving adjuvant endocrine therapy

“…The isoflavones are therefore considered to be possible selective estrogen receptor modulators, which may bind to estrogen receptors and selectively stimulate or inhibit estrogen-like action in various tissues. 2 Given that soy-based foods are now more frequently consumed than was previously the case, both as an alternative approach to treating the symptoms of menopause and for promoting cardiovascular health, 3,4 concerns have arisen about the intake of these compounds by patients with hormone-sensitive breast cancer, in whom tumour growth depends largely on estrogen. Tamoxifen and anastrozole are commonly used as adjuvant endocrine therapy for hormone-sensitive breast cancer, and these drugs are effective in preventing recurrence and prolonging survival.…”