Soy foods may curb hip fracture risk in older women

By Joene Hendry

NEW YORK (Reuters Health) - Postmenopausal women may lessen their chances of fracturing a hip by adding soy-based foods to their diet, a study from Singapore hints.

Women in the study were 21 to 36 percent less likely to fracture a hip when they reported eating a moderate amount of soy, Dr. Woon-Puay Koh, at the National University of Singapore, and colleagues found.

In their study, daily moderate soy intake was at least 2.7 grams of soy protein, 5.8 milligrams of soy isoflavones per 1000 calories, or the equivalent of 49.4 grams of tofu.

This level of soy is consistently "higher than the low levels of consumption in the West," Koh told Reuters Health in an email.

Koh's team assessed dietary soy intake of more than 63,000 Chinese men and women who were 45 to 74 years old when, between 1993 and 1998, they enrolled in the Singapore Chinese Health Study.

Follow-up through the end of 2006 showed 276 men and 692 women had fractured a hip.

The men were about 71 years old and the women about 73 years old, on average, when they suffered the fracture, the investigators report in the American Journal of Epidemiology.

As mentioned, moderate soy intake was associated with a reduced risk of hip fracture among women, but not among men.

The current findings are consistent with those of a previous investigation in postmenopausal Chinese women in Shanghai who showed a 30 percent reduced risk for hip fracture among those consuming higher amounts of soy.

Koh and colleagues surmise that the bone-protective effects of soy isoflavones may play a critical role in the bone health of postmenopausal women.

They call for further investigations to confirm and clarify this association.

SOURCE: American Journal of Epidemiology, October 1, 2009