Owing to its interaction with alcohol, folate has been suggested to be a potential protective factor for many types of cancer. The impact of these factors on the risk of breast cancer among Asian populations has not been fully examined, particularly with respect to receptor status. Researchers carried out a case-control study in premenopausal and postmenopausal Japanese women, including 1,754 breast cancer patients and 3,508 non cancer controls.
The researchers determined the association between self-reported alcohol drinking, dietary folate intake, and the risk of breast cancer. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using logistic models adjusted for potential confounders.
Alcohol consumption was associated with the risk of breast cancer. The OR for a drinker consuming 23g of alcohol or more per day relative to a nondrinker was 1.39 (95% CI: 1.07-1.80). A significant inverse association was observed between folate intake and overall risk of breast cancer, with an OR of 0.79 (95% CI: 0.68-0.93; Ptrend=0.004) for the highest tertile relative to the lowest. The OR of a drinker consuming 23g or more per day relative to a nondrinker with a low folate intake was 1.58 (95% CI: 1.06-2.33). However, a significantly increased risk was not observed in tertile 2 and tertile 3 folate intake with any amount of alcohol consumption.
The authors conclude that higher folate intake decreases the risk of breast cancer among Japanese, whereas alcohol intake increases the risk. These two factors interact with each other, and the excess risk of breast cancer with alcohol consumption might be attenuated by increasing the intake of folate. In addition, the effects of folate/alcohol may vary according to the tumor subtype.
Source: Alcohol and dietary folate intake and the risk of breast cancer: a case-control study in Japan. Islam T, Ito H, Sueta A, Hosono S, Hirose K, Watanabe M, Iwata H, Tajima K, Tanaka H, Matsuo K. Eur J Cancer Prev. 2012 Nov 20.