Polyunsaturated fatty acid interactions and breast cancer incidence: a population-based case-control study on Long Island, New York
Menée aux Etats-Unis auprès de 1 463 cas et 1 500 témoins, cette étude évalue l'association entre une consommation d'acides gras poly-insaturés et le risque de cancer du sein, chez des populations de type occidental
Purpose : Experimental studies demonstrate that ω-3 polyunsaturated fatty acids (PUFAs) inhibit inflammatory eicosanoids generated by ω-6 PUFAs. Epidemiologic studies on dietary ω-3 PUFA intake show consistent inverse associations with breast cancer incidence among Asian populations, where ω-3, relative to ω-6, intake is high. In contrast, associations are inconsistent among Western populations, where intake of ω-3, relative to ω-6, intake is low. We hypothesized that examining interactions between ω-3 and ω-6 would help elucidate the PUFA-breast cancer association in the U.S. Methods : In a Long Island, NY, population-based study of 1463 breast cancer cases and 1500 controls, we estimated multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression to examine interactions between ω-3 and ω-6 intake. Results We observed a super-additive interaction (Relative Excess Risk Due to Interaction=0.41; 95%CI=0.06,0.76) between ω-3 and ω-6 intake in association with breast cancer incidence, although the CIs for the joint exposure of low ω-3/high ω-6 compared to high ω-3/low ω-6 intake were wide (OR=1.20; 95%CI=0.85,1.69). Conclusions : Breast cancer risk reduction may be possible for U.S. women with dietary consumption of higher ω-3, which have anti-inflammatory properties, in concert with lower ω-6, which induce inflammation. Replication from future U.S.-based investigations is needed.