The J-shaped association between alcohol consumption and breast cancer: A case-control study

Background: Alcohol is considered to be a co-carcinogen as well as a tumor promoter, with several studies showing a linear dose-dependent association. However, moderate alcohol consumption has been found to be protective as far as cardiovascular diseases are concerned. Objective: The aim of this study was to evaluate the association of alcohol intake with breast cancer. Design: It is a case - control study. Patients: Two hundred and fifty consecutive newly (within six months) diagnosed breast cancer patients with first developed breast cancer (56±12 years) and 250 age-matched controls were studied. Main Outcome Measures: A special questionnaire assessing various socio-demographic, clinical, lifestyle and dietary characteristics, was applied through face-to-face interviews. Moreover, frequency of alcohol intake (i.e., never, rarely, 3-4 times/month, 1-2 times/week, 3-4 times/week, daily) and type (i.e., red or white wine, beer, whisky, other beverages) of alcoholic beverages consumed were also recorded. Adherence to the Mediterranean diet was evaluated using the MedDietScore (theoretical range 0-55). Results: Alcohol drinking on a weekly basis (i.e., 3-4 times/week) was associated with lower likelihood of having breast cancer (OR=0.16; 95%CI 0.03, 0.80), while higher consumption showed opposite results. Moreover, it was revealed that wine drinking was associated with lower odds of breast cancer (OR=0.60; 95%CI 0.35, 1.00) with no significant differences between red or white wine. Limitations: The major limitation of this study was the potential recall bias. Conclusions: Moderate alcohol intake, and especially wine consumption, seem to be associated with breast cancer prevention.