Background: Epidemiological studies suggest a relation between breast cancer, diet and life styles.
Aim: To analyze the association between food patterns, obesity, smoking, alcohol consumption and breast cancer risk in women of Santiago.
Patients and methods: A case-control study design (170 cases and 340 controls), matched by age and sex, was used. Through a food frequency questionnaire the average daily intake of vegetables, fruits, beta-carotene, vitamin A, C, E and fiber was analyzed. Other exposures to non-nutritional risks (parity, smoking, cancer history) were also studied. Conditional logistic regression was calculated to determine the odds ratio associated with variations in food and nutrient intake and non-nutritional factors.
Results: Cases had a greater BMI and a higher prevalence of obesity than controls (p < 0.02). No differences were observed in either group food patterns. The ORs for breast cancer associated with obesity and alcohol consumption were 1.65 (95% CI 1.06-2.64) and 1.61 (95% CI 1.06-2.54) respectively (p < 0.05). Multiparity had a protective effect with 0.66 less risk (95% CI 0.44-0.99). No protective effect associated to a greater intake of vegetables, fruits or natural antioxidants was observed. Multivariate analysis model disclosed obesity as a risk factor (OR 1.79, p < 0.02) and parity > or = 4 as protective (OR 0.62, p < 0.02).
Conclusions: This study does not support a protective role for natural antioxidants against breast cancer but indicate a weak association with obesity.