The levels of caffeine in your blood could affect the amount of body fat you carry, a factor that in turn could determine your risk of developing type 2 diabetes and cardiovascular diseases.
Those are the findings of a recent study that used genetic markers to establish a more definitive link between caffeine levels, BMI, and type 2 diabetes risk.
The research team, from the Karolinska Institute in Sweden, the University of Bristol in the UK, and Imperial College London in the UK, said calorie-free caffeinated drinks could be explored as a potential means of helping reduce body fat levels.
"Genetically predicted higher plasma caffeine concentrations were associated with lower BMI and whole body fat mass," the researchers wrote in their paper, published in March.
"Furthermore, genetically predicted higher plasma caffeine concentrations were associated with a lower risk of type 2 diabetes. Approximately half of the effect of caffeine on type 2 diabetes liability was estimated to be mediated through BMI reduction."
The study involved data from just under 10,000 people collected from existing genetic databases, focusing on variations in or near specific genes known to be associated with the speed at which caffeine is broken down
In general, those with variations affecting the genes – namely CYP1A2 and a gene that regulates it, called AHR – tend to break caffeine down more slowly, allowing it to remain in the blood longer. Yet they also tend to drink less caffeine in general.