Consumption of alcohol has been positively associated with breast cancer risk in epidemiologic studies, but the mechanism by which alcohol might increase risk for breast cancer is not known. One possibility is that alcohol changes the metabolism of two vitamins, folate and vitamin B12, and the changes in these vitamins affects DNA stability and synthesis.
While the effects of excessive consumption of alcohol on folate and vitamin B12 metabolism are well-known, the effects of moderate alcohol consumption are not. In this study, researchers investigated the effects of moderate consumption of alcohol (1 or 2 drinks each day) in fifty-three postmenopausal, healthy, well-nourished women.
Each woman received in a random order, no drinks, one drink or two drinks per day for 8-weeks. After eight weeks, blood was collected and analyzed for serum folate, vitamin B12, homocysteine (HCY), and methylmalonic acid (MMA) concentrations.
After correcting for body mass index, there was a 5% decrease in the amount of serum vitamin B12 concentrations from 0 to 1 drink/d treatment. Alcohol intake had no significant effects on serum folate or MMA and HCY concentrations. Among healthy, well-nourished, postmenopausal women, moderate alcohol intake may diminish vitamin B12 status.
These data are important for post-menopausal women who are interested in making dietary choices that can decrease risk for disease, as well as health professionals and policy makers who provide guidelines concerning alcohol consumption.
Source: Laufer EM, HartmanTJ, Baer DJ, Gunter EW, Dorgan JF, Campbell WS, Clevidence BA, Brown ED, Albanes D, Judd JT, 2004. The Effects Of Moderate Alcohol Consumption Of Folate And Vitamin B12 Status In Postmenopausal Women. European Journal Of Clinical Nutrition.