Systematic review and meta-analysis suggest that dietary cholesterol intake increases risk of breast cancer

Several epidemiological investigations have been conducted to evaluate the relationship between dietary cholesterol intake and risk of breast cancer, but the results are inconsistent. This meta-analysis was performed to summarize the evidence from observational studies to test the hypothesis that dietary cholesterol intake increases the risk of breast cancer. PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure were searched for relevant articles published up to July 2015. Pooled relative risks were calculated with random effects model. Dose-response relationship was assessed by restricted cubic spline model. Overall, 9 articles involving 6 cohort studies and 3 case-control studies were included in this study. The pooled relative risk with 95% confidence intervals of breast cancer for the highest vs lowest category of dietary cholesterol intake was 1.29 (1.06-1.56). For dose-response analysis, a nonlinear relationship was found between dietary cholesterol and breast cancer, and the association became statistically significant when the cholesterol intake was greater than 370 mg/d. Results from this meta-analysis indicated that dietary cholesterol was associated with an increased risk of breast cancer.