Conformity to traditional Mediterranean diet and breast cancer risk in the Greek EPIC (European Prospective Investigation into Cancer and Nutrition) cohort.
BACKGROUND
Studies in the United States report inverse associations of the Mediterranean dietary pattern with breast cancer risk, and several studies in Mediterranean countries indicate inverse associations of breast cancer risk with intake of olive oil, a constitutional component of this diet. No study, however, has evaluated the association of the traditional Mediterranean diet with breast cancer in a Mediterranean country.


OBJECTIVE
We studied the relation of conformity to the Mediterranean diet with breast cancer risk in the context of the European Prospective Investigation into Cancer and Nutrition cohort in Greece.


METHODS
We followed up 14,807 women for an average of 9.8 y and identified 240 incident breast cancer cases. Diet was assessed through a validated food-frequency questionnaire, and conformity to the Mediterranean diet was evaluated through a score (range = 0-9 points) incorporating the characteristics of this diet.


RESULTS
Increasing conformity to the Mediterranean diet was not associated with lower breast cancer risk in the entire cohort [hazard ratio (HR) = 0.88 for every 2 points; 95% CI: 0.75, 1.03] or in premenopausal women (HR = 1.01 for every 2 points; 95% CI: 0.80, 1.28), but there was a marginally significant inverse association among postmenopausal women (HR = 0.78 for every 2 points; 95% CI: 0.62, 0.98; P for interaction by menopausal status = 0.05).


CONCLUSIONS
Conformity to the traditional Mediterranean diet may be associated with lower breast cancer risk among postmenopausal women and could explain, in part, the lower incidence of this disease in Mediterranean countries.
Trichopoulou
Antonia
A
WHO Collaborating Center for Food and Nutrition Policies, Department of Hygiene, Epidemiology and Medical Statistics, Athens, Greece.
Bamia
Christina
C
Lagiou
Pagona
P
Trichopoulos
Dimitrios
D
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D004034:Diet Surveys; D038441:Diet, Mediterranean; D005260:Female; D006115:Greece / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D017698:Postmenopause; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires