ACCORDING to a new study, a high level of caffeine in the blood could curb body fat and the risk of type 2 diabetes. However, this effect may only be apparent in individuals with a certain genetic predisposition.


Previous studies had already established a link between coffee consumption and a reduced risk of diabetes. But this research remained observational. A new study, conducted by researchers from the Karolinska Institute, the University of Bristol and Imperial College London, used another approach to test this hypothesis: genetics.

For the purposes of their study, the researchers used the Mendelian randomization technique, which establishes causation through genetic evidence. The researchers identified two common genetic mutations that affect the rate of caffeine metabolism in the body, CYP1A2 and AHR.

As a result, blood caffeine levels could be sequenced and analyzed to see if they were associated with a lower BMI and a lower risk of diabetes.

From a sample of around 10,000 people, the researchers noticed that people with variations in these two genes metabolize caffeine more slowly. They don't need to drink a lot of caffeinated beverages to benefit from the stimulant's effects, because its absorption is more effective.

These people have higher levels of caffeine in their blood than people who metabolize caffeine more quickly.

The results also showed that people with high levels of caffeine in their blood have a lower BMI and body fat than others. They also have a lower risk of type 2 diabetes.

"Our mendelian randomization finding suggests that caffeine might, at least in part, explain the inverse association between coffee consumption and risk of type 2 diabetes," said Dr Susanna Larsson, associate professor in the Institute of Environmental Medicine at the Karolinska Institute, and lead author of the paper, quoted in a news release.

However, the researchers acknowledge various limitations to their findings, including the use of only two genetic variants and the inclusion of individuals primarily of European descent.

Still, the study may offer promising new solutions to treatment of obesity and type 2 diabetes.

Benjamin Woolf, PhD student in the Tobacco and Alcohol Research Group at the University of Bristol, co-author who led on the statistics for the paper, added: "Randomized controlled trials are warranted to assess whether non-caloric caffeine containing beverages might play a role in reducing the risk of obesity and type 2 diabetes."