Author
Yan, Lin | |
SPITZNAAGEL, EDWARD - Washington University | |
BOSLAND, MAARTEN - University Of Illinois |
Submitted to: Cancer Epidemiology Biomarkers and Prevention
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/9/2009 Publication Date: 1/10/2010 Citation: Yan, L., Spitznaagel, E.L., Bosland, M.C. 2010. Soy Consumption and Colorectal Cancer Risk in Humans: A Meta-Analysis. Cancer Epidemiology Biomarkers and Prevention. 19(1):148-158. Interpretive Summary: Soy is a major plant source of dietary protein to humans. Consumption of soy foods is considered to be beneficial to human health, for example, an improvement of heart health. Colorectal cancer is the third leading cause of deaths from cancer to both men and women in the United States. We examined the relationship between soy consumption and colorectal cancer risk by conducting a meta-analysis (statistical analysis) of findings from 11 epidemiologic studies (population studies). When separately analyzed on the basis of gender, we found soy was associated with an approximately 21% reduction in colorectal cancer risk in women, but not in men. Thus, consumption of soy foods may be associated with a reduction in colorectal cancer risk in women, but not in men. Technical Abstract: The purpose of the present study was to determine the relationship between soy consumption and colorectal cancer risk in humans by conducting a meta-analysis of available epidemiologic studies. We systematically reviewed publications obtained through a Medline literature search and identified four cohort and seven case-control studies on soy and colorectal cancer risk that met the inclusion criteria. We extracted the risk estimate (hazard ratio, relative risk or odds ratio) of the highest and the lowest reported categories of intake from each study and conducted this analysis using a random-effects model. Our analysis did not find that soy consumption was associated with colorectal cancer risk (combined risk estimate: 0.90, 95% CI: 0.79, 1.03) nor the separate analyses on colon cancer (combined risk estimate: 0.88, 95% CI: 0.74, 1.06) and rectal cancer (combined risk estimate: 0.88, 95% CI: 0.67, 1.14). However, when separately analyzed on the basis of gender, we found soy was associated with an approximately 21% reduction in colorectal cancer risk in women (combined risk estimate: 0.79, 95% CI: 0.65, 0.97; P = 0.026), but not in men (combined risk estimate: 1.10, 95% CI: 0.90, 1.33). Thus, consumption of soy foods may be associated with a reduction in colorectal cancer risk in women, but not in men. |