A meta-analysis by the Centre for Addiction and Mental Health in Toronto, Canada examined the relationship between the consumption of alcoholic beverages and the risk of type 2 diabetes.
20 cohort studies with longitudinal design and the quantitative measurement of alcohol intake were included. For the first time, lifetime abstention was used as the reference category and the data were adjusted for the ‘sick-quitter’ effect. The dose- response relationship in men and women as well as the development of type 2 diabetes were explored using lifetime abstainers as the reference group.
An U-shaped association was found for both sexes. For women, at 24g of alcohol/day, the protective effect from developing type 2 diabetes was seen to be the greatest, with a risk reduction of 40% compared to lifetime abstainers. This benefit was observed up to a daily intake of just below 50g/day. For men, the protective effect was highest at 22g/day, with a risk reduction of 13% compared to lifetime abstainers and was observed up to an intake of 60g/day.
The authors discuss various biological mechanisms for such a risk reduction, including increases in insulin sensitivity after moderate consumption of alcoholic beverages, changes in levels of metabolites of alcohol, increases in HDL cholesterol concentration and the anti-inflammatory effect of alcohol.
The authors conclude that this meta analysis confirms previous research findings that moderate consumption of alcoholic beverages is protective for type 2 diabetes in men and women.
Source: Baliunas DO, Taylor BJ, Irving H, et al. Alcohol as a risk factor for type 2 diabetes: A systematic review and meta-analysis. Diabetes Care 2009;32:2123-32.