Study suggests high caffeine levels may reduce risk of type 2 diabetes

A new study has suggested that having higher levels of caffeine in your blood may lower body fat and also reduce the risk of type 2 diabetes. The study, published online in the BMJ Medicine journal on Tuesday (March 14), said the objective (of the study) was to investigate the potential causes of long-term plasma caffeine concentrations on adiposity, type 2 diabetes, and major cardiovascular diseases.

Explaining that caffeine has thermogenic effects, the researchers noted that previous studies linked caffeine intake with reductions in weight and fat mass. And observational data showed associations between coffee consumption with lower risks of type 2 diabetes and cardiovascular disease.

The researchers used data from studies of mainly European populations to examine two specific genetic mutations that have been linked to a slower speed of caffeine metabolism.

Using Mendelian randomisation, Susanna C. Larsson, PhD, of the Karolinska Institute, Stockholm, Sweden and colleagues examined data that came from a genome-wide association meta-analysis of 9,876 individuals of European ancestry from six population-based studies.

"Genetically predicted, lifelong, higher plasma caffeine concentrations were associated with lower body mass index and fat mass, as well as a lower risk of type 2 diabetes," the study said. It added that approximately half of the effect of caffeine on this chronic condition was estimated to be mediated through body mass index (BMI) reduction.

The study also highlighted that small and short-term trials showed that caffeine intake resulted in weight and fat mass reduction, but the long-term effects were unknown.

"Consumption of coffee, a rich source of caffeine, is observationally associated with a lower risk of type 2 diabetes and cardiovascular disease," it said.

Dr Stephen Lawrence from Warwick University in the United Kingdom (UK) noted that the finding supported existing studies suggesting a link between caffeine consumption and increased fat burn, according to a report by Medscape.

Speaking to the UK Science Media Centre, Dr Lawrence said, "The big leap of faith that the authors have made is to assume that the weight loss brought about by increased caffeine consumption is sufficient to reduce the risk of developing type 2 diabetes."

"It does not, however, prove cause-and-effect," he said.

On the other hand, Katarina Kos, a senior lecturer in diabetes and obesity at the University of Exter, said this study showed links and potential health benefits for people "with certain genes attributed to a faster [caffeine]...metabolism as a hereditary trait and potentially a better metabolism." Kos added the research did not study or recommend drinking more coffee, which was not the purpose.