Dietary patterns and breast cancer: a case-control study in women.

PURPOSE
Since dietary habits have been associated with breast cancer, the tested research hypothesis was the associations between food patterns, as derived through multivariate methods, and breast cancer.

METHODS
In a case-control study, Two-hundred and fifty consecutive, newly diagnosed breast cancer female patients (56 ± 12 years) and 250 one-to-one age-matched, healthy controls were studied. A standardized, validated questionnaire assessing various socio-demographic, clinical, lifestyle, and dietary characteristics was applied through face-to-face interviews. Factor analysis, with principal components method, was applied to extract dietary patterns from 86 foods or food groups consumption reported by the controls.

RESULTS
Three components were derived explaining 43 % of the total variation in consumption. Component 1 was characterized by the consumption of potatoes, red meat and its products, poultry and white meat, dairy products, use of margarine/butter in cooking or at the table, consumption of sausages, fried food as well as grilled meat or fish; component 2 was characterized by the consumption of whole grains, fruits, and vegetables; and component 3 was characterized by olive oil and fish consumption. After adjusting for various confounders, components 2 and 3 were favorably associated with the absence of having breast cancer [odds ratio (OR) 0.60, 95 % CI 0.47-0.75 and OR 0.81, 95 % CI 0.66-0.99, respectively], while component 1 was not significantly associated with the disease.

CONCLUSIONS
Adherence to healthy dietary patterns (including whole grains, fruits, and vegetables, olive oil, and fish) seems to be favorable in not having breast cancer, among middle-aged women.