Soy Foods and the Risk of Fracture: A Systematic Review of Prospective Cohort Studies

<b><i>Objectives:</i></b> The primary objective of our study was to systematically review all available prospective cohort studies which investigated the association of soy food intake and incident fracture risk. <b><i>Methods:</i></b> We searched PubMed, Scopus, and Embase databases for relevant studies up to June 2021. <b><i>Synthesis:</i></b> Of 695 records, a total of 5 cohort studies were included in the current systematic review. Two studies that were performed in China evaluated hip fracture while 2 studies that were done in Singapore evaluated any kind of fractures. The other study was conducted in Japan and evaluated osteoporosis fractures. All studies used a face-to-face interview to assess the dietary intake of soy foods. All 5 cohort studies were determined to be of high quality. One study considered soy food as a part of a vegetables-fruit-soy food dietary pattern. Others reported the association of dietary intake of soy foods with the risk of fractures. <b><i>Conclusion:</i></b> The evidence from prospective cohort studies was suggestive for a protective role of soy foods, alone or within a dietary pattern, in the risk of incident fracture among Asian women, particularly for those in early menopause and those who used fermented soy products. But for men, the association was not significant. However, more cohort studies, including non-Asian populations, are required to confirm this association fully.