The Effect of Omega-3 Intake on Colorectal Cancer

Colorectal cancer is one of the most common cancers among men and women in the world. Of all the risk factors of colorectal cancer, nutritional factors are among the most important and preventable risk factors. Epidemiological studies as well as laboratory evidence have investigated the effect of omega-3 intake in the prevention of colorectal cancer, and considering the contradictory results in this area, the present study was conducted to investigate the effect of this nutrient on colorectal cancer.

In this systematic review and meta-analysis, eligible studies were carefully and independently searched by two researchers using the keywords “colorectal cancer” or “colon cancer”, “Omega 3 fatty acids”, “fish oil”, “n-3 PUFAs” and “ω-3” in ISI, PubMed, Scopus, ProQuest and Embase databases from 1993 till the end of 2017, and the search was restricted to English language. The abbreviations RR, OR, and HR were extracted with a 95% confidence interval and subjected to statistical analysis based on the random effects model.

Among 6554 articles, 15 prospective cohort studies were finally included in the research. Despite the lower rate of colorectal cancer in both genders (p=0.394, 95% CI: 0.85-1.06, RR: 0.95) as well as men (p=0.395, 95% CI: 0.79-1.09, RR: 0.93) and women (p=0.583, 0.74-1.17, 95% CI: 0.74-1.17, RR: 0.93) who consumed omega-3, no statistically significant difference was found between consumers and non-consumers.

The results of this study demonstrated that there was no significant relationship between the intake of omega-3 and its subtypes and the incidence of colorectal cancer.