The results of a meta-analysis published in a recent issue of the American Journal of Clinical Nutrition add evidence to preliminary findings concerning a protective effect for soy against the development of lung cancer.*
Yong-Bing Xiang of Shanghai Jiaotong University School of Medicine and colleagues selected eight case-control and three prospective cohort studies for their review, which included 8,436 cases of lung cancer. The analysis uncovered a 23% reduction in lung cancer risk in association with high versus low soy consumption. When the analysis was limited to five studies of high quality, a 30% reduction was revealed. In analyses of specific groups, significant protective effects were observed for women, people who have never smoked, and Asian populations. For studies that documented intake of soy isoflavones, an approximate 27% reduction in lung cancer risk was associated with high intake.
Editor’s Note: While unfermented soy foods were associated with a protective effect, fermented foods such as miso were not.