ω-3 and ω-6 polyunsaturated fatty acid intakes and the risk of breast cancer in Mexican women: impact of obesity status
Menée en population mexicaine (1 000 cas et 1 074 témoins), cette étude évalue l'influence d'une obésité sur l'association entre un régime alimentaire riche en acides gras oméga-3 et oméga-6 et le risque de cancer du sein
Background:ω-3 polyunsaturated fatty acids (PUFA) have been hypothesized to encompass a potential for preventive strategies targeted on breast cancer risk. Little is known about the relationship between ω-3 PUFA intake and breast cancer risk among Mexican women. We evaluated the association between ω-3 and ω-6 PUFA intake and breast cancer risk by obesity status in Mexican women. Methods:A population-based case-control study was conducted in Mexico, including 1,000 incident breast cancer cases and 1,074 controls matched to cases by age, health-care system, and region. Women provided information on health and diet by means of an in-person interview. Body mass index (BMI) measures were used to define overall obesity. Obesity status was categorized as normoweight (18.5<BMI<25), overweight (25javascript:app('less%20than%20or%20equal%20to')BMI<30) and obese (BMIjavascript:app('greater%20than%20or%20equal%20to')30). A conditional logistic regression model was used to assess the association between PUFA and breast cancer risk. Results:Overall, there was no significant association between ω-3 PUFA intake and breast cancer risk (p=0.31). An increased risk of breast cancer was associated with increasing ω-6 PUFA intake in pre-menopausal women (OR=1.92, 95% CI=1.13;3.26; p=0.04). A decreased risk of breast cancer was significantly associated with increasing ω-3 PUFA intake in obese women (OR=0.58, 95%CI=0.39;0.87; p=0.008), but not in normoweight nor in overweight women (p for heterogeneity = 0.017). Conclusions:Obesity status may affect the association between ω-3 PUFA intake and breast cancer risk. The underlying mechanisms may be related to decreased inflammation and improved adipokin and estrogen levels induced by ω-3 PUFA in adipose tissue in obese women. Impact: ≤≤