Dietary Fat Intake and Risk of Colorectal Cancer: A Systematic Review and Meta-Analysis of Prospective Studies

Dietary fat intake is associated with the risk of colorectal cancer (CRC); however, the results of epidemiological studies on this are controversial. Therefore, this study aimed to summarize the available scientific evidence regarding the association between dietary fat and the risk of CRC. We conducted a systematic search of PubMed, Web of Science, and the Cochrane library for articles related to dietary fat and the risk of CRC. The summary relative risks with 95% confidence intervals (CI) were calculated via a random effect model. Begg's test was used to detect publication bias. A total of 18 articles were identified. The pooled relative risk with 95% CI for the risk of CRC were 1.00 (95% CI: 0.90-1.12), 0.97 (95% CI: 0.86-1.10), 1.08 (95% CI: 0.92-1.26), and 0.99 (95% CI: 0.93-1.04) for total fat, saturated fatty acid, monounsaturated fatty acid, and polyunsaturated fatty acid, respectively. No significant associations were found in subgroup analyses. Begg's test for all exposures revealed no publication bias (total fat, p = 0.3; saturated fatty acid, p = 0.1; monounsaturated fatty acid, p = 0.08; polyunsaturated fatty acid, p = 0.2). The studies included in this review and meta-analysis revealed that dietary fats and fatty acids had no effects on the risk of CRC.