Submitted to: European Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/8/2004
Publication Date: 5/12/2004
Citation: Laufer, E.M., Hartman, T.J., Baer, D.J., Gunter, E.W., Dorgan, J.F., Campbell, W.S., Clevidence, B.A., Brown, E.D., Albanes, D., Judd, J.T. 2004. The effects of moderate alcohol consumption of folate and vitamin B12 status in postmenopausal women. European Journal of Clinical Nutrition. 58:1518-1524.
Interpretive Summary: 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, we do not know about the effects of moderate alcohol consumption. In this study, we investigated the effects of moderate consumption of alcohol (1 or 2 drinks each day) in fifty-three postmenopausal, healthy, well-nourished women. Each women received either 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 postmenopausal women who are interested in making dietary choices that can decrease risk for disease, as well as health professionals and policy makers who provide recommendations concerning alcohol consumption.
Technical Abstract: Although alcohol intake has been positively associated with breast cancer risk in epidemiologic studies, a causal relationship has not been established, and the mechanisms mediating this association are speculative. Alcohol may act through altered status of folate and vitamin B12, two vitamins required for DNA methylation and nucleotide synthesis, and thus cell integrity. Although the effects of heavy alcohol intake on folate and vitamin B12 status have been well-documented, few studies have addressed the effects of moderate alcohol intake in a controlled setting. The objective of the study was to determine the effects of moderate alcohol intake on folate and vitamin B12 status in healthy, well-nourished, postmenopausal women. The study design was a randomized, diet-controlled crossover intervention. Postmenopausal women (n=53) received three 8-week alcohol treatments in random order: 0 g/d, 15 g/d, and 30 g/d. Treatment periods were preceded by 2- to 5-week washout periods. Blood collected at baseline and week eight of each treatment period was analyzed for serum folate, vitamin B12, homocysteine (HCY), and methylmalonic acid (MMA) concentrations. After adjusting for body mass index (BMI), a significant 5% decrease was observed in mean serum vitamin B12 concentrations from 0 to 30 g of alcohol/d (461.45±30.26 pg/mL versus 440.25±30.24 pg/mL; P=0.03). Mean serum HCY concentrations tended to increase by 3% from 0 to 30 g of alcohol/d (9.44±0.37 micromol/L versus 9.73±0.37 micromol/L; P=0.05). Alcohol intake had no significant effects on serum folate or MMA concentrations. Among healthy, well-nourished, postmenopausal women, moderate alcohol intake may diminish vitamin B12 status.