Background: Breast cancer mortality and incidence rates in the Canary Islands, and particularly in Gran Canaria, are higher than those in the rest of Spain.
Objectives and design: A case-control study was designed to assess the role of differential fatty acid intakes and olive oil consumption on breast cancer risk in the Canary Islands. The study was conducted between 1999 and 2001, including a total of 755 women: 291 incident cases with confirmed breast cancer and 464 controls randomly selected from the Canary Island Nutrition Survey (ENCA). A semi-quantitative food-frequency questionnaire was completed and potential confounders were adjusted using unconditional logistic regression.
Results: Compared to the first quintile of intake, the highest quintile of monounsaturated fat intake was significantly related to a lower risk of breast cancer (odds ratio = 0.52; 95% CI 0.30-0.92). Regarding olive oil, the odds ratio for women in the three upper quintiles of consumption (> or =8.8 g/day) was 0.27 (95% CI 0.17-0.42).
Conclusion: Our results support the protective role of olive oil consumption on breast cancer among Canaries women.