Latest scientific news 25 February 2016

Light to moderate consumption of alcoholic beverages can protect from type-2 diabetes

The findings of the current meta-analysis suggest that low to moderate consumption of alcoholic beverages is associated with a lower risk of type-2 diabetes and shows a clear dose-response relationship.

Type-2 diabetes (T2D) has reached epidemic proportions with an estimated 347 million people affected worldwide and more than 1.3 million T2D related deaths globally. A major cause of premature illness and death in individuals with T2D are cardiovascular diseases, the leading cause of death in the industrialized world. Prevention of T2D is therefore of the outmost importance.

Several modifiable risk factors like obesity and physical inactivity play an important role in the development of T2D. On the other hand, previous cohort studies and meta-analyses have shown that moderate consumption of alcoholic beverages is associated with a lower risk of T2D. It remains controversial, however, whether the benefits of moderate drinking differ according to factors such as sex, age, BMI, smoking status, physical activity, and family history of T2D. A group of Chinese researchers conducted a comprehensive systematic review and meta-analysis with 706,716 participants (275,711 men and 431,005 women) and 31,621 cases of T2D to evaluate whether the consumption of alcoholic beverages affects the diabetes risk in the various age and lifestyle factor sub-groups differently. In addition, the researchers examined the dose-response relationship between alcohol consumption and T2D risk. This is important for the strength of the statistical association: if the dose-response association can be reproduced, the results are not random but support a causal relationship.

The results (of all the pooled data) showed that compared to the lowest category of alcohol consumption, light (up to 12g of alcohol) and moderate drinking (12-24 g of alcohol) was associated with a 17 % and a 26 % lower risk of T2D, respectively.

The analysis of the sub-groups showed that there was no noticeable difference: all sub-groups benefited from light to moderate alcohol intake and age, sex, family history of T2D as well as lifestyle factors seemed to have little influence. A nonlinear relation between the consumption of alcoholic beverages and the risk of T2D was identified in men and in women. The risk of T2D decreased with a consumption of up to 20g of alcohol in women and up to 40 g in men, above these amounts the risk increased.

As a possible protective mechanism, the scientists speculated that low to moderate consumption of alcoholic beverages is associated with increased insulin sensitivity and a lower fasting insulin resistance, which might play an important role in the progression of T2D. Indeed previous meta-analyses had pointed out that moderate alcohol intake could lower glycated hemoglobin concentrations.

In summary, it seems biologically plausible that moderate alcohol consumption is causally related to a lower diabetes risk.

Li XH, Yu FF, Zhou YH, He J. Association between alcohol consumption and the risk of incident type 2 diabetes: a systematic review and dose-response meta-analysis. Am J Clin Nutr. 2016 Feb 3. pii: ajcn114389. [Epub ahead of print]

For more information about this article, read the scientific abstract here.