A study conducted on 24,000 post menopausal women in China showed that soy may help them reduce their risk of bone fractures.
The women were divided into five groups, according to their soy intake. Those in the lowest-intake group consumed less than 5 grams of soy per day while those in the highest-intake group consumed 13 grams or more per day. Women were interviewed in their homes by trained interviewers using a structured questionnaire, and were followed with food frequency questionnaires and in-person interviews. The results showed that women from the highest-soy intake group had 35-37% less risk of fractures. The authors found that as dietary soy intake went up, fracture risk went down.
Experts believe that it is isoflavones, plant-based estrogen-like soy compound that helps strengthen bones.
The researchers also said this was only an observational study and that they can't establish a causal link between soy consumption and reduced fracture risk because of differences in baseline disease risk factors, life-style factors, or other dietary components.