Can Folate Block Some of Alcohol’s Potential Harms?

Two recent studies examined whether folate intake moderates alcohol’s effects on health outcomes. In the first study, researchers from Australia followed 17,447 women (aged 40–69 years at recruitment) for 9–13 years to assess whether folate affected breast cancer risk among moderate drinkers. During follow-up, 537 invasive breast cancers were diagnosed (according to a cancer registry).

• In analyses adjusted for potential confounders (e.g., total calorie intake), women who consumed an average of >=3 drinks per day at baseline had a nonsignificantly higher hazard of breast cancer than did abstainers* (hazard ratio [HR] 1.4).
• Folate intake was not directly associated with risk of breast cancer. However, a high folate intake mitigated the risk associated with drinking. The hazard ratio of breast cancer associated with drinking >=3 drinks per day (compared with abstaining) was
  • 2.0 for women with a daily folate intake of 200 μg;
  • 0.8 (a nonsignificant difference) for those with a daily intake of 400 μg.

In the second study, researchers conducted a cross-sectional analysis of 988 women to assess the relationship between alcohol, folate, and homocysteine (which, when elevated, raises the risk of heart disease). Analyses were also adjusted for potential confounders.

• Of women with the lowest folate intake (<288 μg of folate per day), those who consumed approximately >=1 drink per day had significantly higher homocysteine levels than did lighter drinkers and nondrinkers.
• The opposite was true for those with the highest folate intake (>720 μg of folate per day): among these women, those who drank >=1 drink per day had significantly lower homocysteine levels than did lighter drinkers and nondrinkers.

Comments:

These studies support previous evidence of folate’s potentially important role in reducing risk of certain health outcomes in moderate drinkers. It appears that women who drink alcohol and also consume sufficient levels of folate may have no increased risk of breast cancer and have lower homocysteine levels.

R. Curtis Ellison, MD

Reference:

Baglietto L, English DR, Gertig DM, et al. Does dietary folate intake modify effect of alcohol consumption on breast cancer risk? Prospective cohort study. BMJ. 2005;331(7502):807.

Chiuve SE, Giovannucci EL, Hankinson SE, et al. Alcohol intake and methylenetetrahydrofolate reductase polymorphism modify the relation of folate intake to plasma homocysteine. Am J Clin Nutr. 2005;82(1):155–162.