Nutritional factors and breast cancer in Mexico.

Breast cancer (BC) morbidity and mortality in Mexico are on the rise, affecting younger women with more frequency. Nutritional factors are often mentioned as determinants of BC but their relevance is not well established in Latin-American countries, where dietary habits show great variation. From a study population previously assembled in Mexico City, 141 histologically confirmed cases of BC were matched by age (+/-3 yr) to an equal number of hospital controls. A food frequency questionnaire was administered to all subjects and the risk of BC was estimated in relation to the intake of selected nutrients. The findings of this study show a protective effect against BC due to a high intake of polyunsaturated fat (odds ratio, OR = 0.10, 95% CI = 0.02-0.40, P for trend = 0.001) and vitamin E (OR = 0.10, 95% CI = 0.02-0.44, P for trend = 0.003) among postmenopausal women. In addition, our findings also suggest that a high intake of total fiber (OR = 0.29, 95% CI = 0.08-1.10, P for trend = 0.080) and carotenes (OR = 0.42, 95% CI = 0.16-1.14, P for trend = 0.088) lowers BC risk among premenopausal women. The relationship between the intake of nutrients and BC risk needs further confirmation.