Moderate Alcohol Consumption Lowers the Risk of Type 2 Diabetes

A meta-analysis of prospective observational studies

  1. Lando L.J. Koppes, PHD12,
  2. Jacqueline M. Dekker, PHD1,
  3. Henk F.J. Hendriks, PHD3,
  4. Lex M. Bouter, PHD1 and
  5. Robert J. Heine, MD, PHD14
  1. 1Institute for Research in Extramural Medicine (EMGO Institute), VU University Medical Center, Amsterdam, the Netherlands
  2. 2Department of Public and Occupational Health, VU University Medical Center, Amsterdam, the Netherlands
  3. 3Department of Nutritional Physiology, TNO Nutrition and Food Research, Zeist, the Netherlands
  4. 4Department of Endocrinology, VU University Medical Center, Amsterdam, the Netherlands
  1. Address correspondence and reprint requests to Lando L.J. Koppes, PhD, VU University Medical Center, EMGO Institute, Van der Boechorststraat 7, 1081 BT Amsterdam, Netherlands. E-mail: l.koppes{at}


OBJECTIVE—This meta-analysis was undertaken to obtain insight regarding the shape and strength of the relationship between alcohol consumption and the risk of type 2 diabetes, the effects of adjustment for confounders, and the effect of modification by type 2 diabetes definition, sex, and BMI.

RESEARCH DESIGN AND METHODS—The 15 original prospective cohort studies that were included comprise 11,959 incident cases of type 2 diabetes in 369,862 individuals who, on average, were followed for 12 years.

RESULTS—After pooling the data, a U-shaped relationship was found. Compared with nonconsumers, the relative risk (RR) for type 2 diabetes in those who consumed ≤6 g/day alcohol was 0.87 (95% CI 0.79–0.95). For the moderate consumption ranges of 6–12, 12–24, and 24–48 g/day, RRs of 0.70 (0.61–0.79), 0.69 (0.58–0.81), and 0.72 (0.62–0.84) were found, respectively. The risk of type 2 diabetes in heavy drinkers (≥48 g/day) was equal to that in nonconsumers (1.04 [0.84–1.29]). In general, nonsignificant trends for larger RR reduction associated with moderate alcohol consumption were observed for women compared with men, for crude compared with multivariate-adjusted analyses, and for studies that used self-reports instead of testing for type 2 diabetes definition. No differences in RR reductions were found between individuals with low or high BMI.

CONCLUSIONS—The present evidence from observational studies suggests an ∼30% reduced risk of type 2 diabetes in moderate alcohol consumers, whereas no risk reduction is observed in consumers of ≥48 g/day.


    • Accepted November 8, 2004.
    • Received July 30, 2004.
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