Dietary linoleic acid intake in relation to breast cancer: A case-control study.

Background: The present study aimed to investigate the association between dietary linoleic acid (LA) intake and breast cancer in women. Methods: In this population-based case-control study, we enrolled 350 pathologically confirmed breast cancer cases and 700 controls which were matched with cases in terms of age and socioeconomic status. Dietary intakes were assessed using a 106-item Willett-format semi-quantitative dish-based food frequency questionnaire (DS-FFQ). Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were estimated. Results: A significant inverse association was found between LA intake and odds of breast cancer (OR: 0.41, 95% CI: 0.30-0.56). After adjusting for potential confounders, women in the highest tertile of dietary LA intake were 48% less likely to have breast cancer compared with those in the lowest tertile (OR: 0.52, 95% CI: 0.28-0.95). Such a significant inverse association was also seen among normal-weight women (OR: 0.29, 95% CI: 0.14-0.63), and premenopausal women (OR: 0.15, 95% CI: 0.02-0.95). Conclusion: The findings of current study provide evidence for a protective role of LA against breast cancer particularly among normal-weight and premenopausal women. Prospective studies are needed to confirm this association.