Abstract
BACKGROUND: Rectal cancer (RC) is one of the most commonly occurring cancers in Iran in recent years. Dietary intakes of Omega-3 (ω-3), Omega-6 (ω-6), and fiber have been thought to diminish the risk of RC. Therefore, this study was conducted to evaluate the association of dietary ω-3, ω-6, and fiber with the risk of RC. METHODS: In this case-control study, dietary intakes of ω-3 and ω-6 were estimated using a 148-item food frequency questionnaire (FFQ) between 363 people (162 cases, 201 control) aged 20-80 years old. Cases were patients with RC, and controls were healthy people. Odds ratios (OR) and 95% confidence intervals (CI) were assessed using logistic regression models. RESULTS: According to the multiple logistic regression model with the backward method, dietary fiber intake was inversely associated with RC as a protective factor (OR=0.3; 95%CI= 0.1-0.9; P=0.038). Also, it was observed that dietary ω-3 had an inverse borderline association with RC (OR= 0.5; 95%CI= 0.3-1.02; P=0.060), after adjusting for other studied variables. However, the association of ω-6 with RC was not statistically significant (OR=1.1; 95%CI= 0.7-1.8; P=0.730). CONCLUSION: Although no association between ω-3 and ω-6 intake was observed with the risk of RC, adequate daily intake of dietary fiber may protect us against RC risk.