The more soy foods consumed, the lower the risk of fracture, particularly among women in early menopause, say the results of a prospective cohort study.

Researchers studied over 24,000 postmenopausal Chinese women with no history of fracture or cancer. They found that those who ate <4.98, 4.98–7.32, 7.33–9.77, 9.78–13.26, and 13.27 g/d soy protein had relative risks (95% CI) of fracture that were 1.00, 0.72 (0.62–0.83), 0.69 (0.59–0.80), 0.64 (0.55–0.76), and 0.63 (0.53–0.76), respectively. The inverse association persisted independent of major risk factors for osteoporotic fractures and other dietary factors, including intake of calcium, nonsoy protein, fruits, and vegetables.

The researchers found similar results for intake of isoflavones. Scientists suspect soy and soy isoflavones protect the skeleton by suppressing bone resorption.

Zhang X, Shu XO, Li H, et al. Prospective cohort study of soy food consumption and risk of bone fracture among postmenopausal women. Arch Intern Med. 2005;165:1890-1895.