Researchers from the Karolinska Institute, University of Bristol, and Imperial College London have discovered a link between caffeine levels in the blood and body fat. According to the study, higher caffeine levels may be associated with lower body mass index (BMI) and reduced risk of type 2 diabetes. The team used genetic markers to establish a more definitive connection between caffeine consumption and its potential health benefits.
The study found that genetically predicted higher plasma caffeine concentrations were associated with lower BMI and whole-body fat mass. Furthermore, higher plasma caffeine concentrations were linked to a lower risk of type 2 diabetes, with approximately half of this effect attributed to BMI reduction.
"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 2023.
"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."
While the researchers acknowledge limitations to their findings, including the use of only two genetic variants and the inclusion of only people of European ancestry, their results are supported by existing knowledge of caffeine's effects. Caffeine is known to boost metabolism, increase fat burning, and reduce appetite. A daily intake of 100 mg of caffeine has been estimated to increase energy expenditure by around 100 calories, potentially lowering the risk of obesity.
The researchers suggest that their findings may explain the inverse association between coffee consumption and type 2 diabetes risk. They conclude that randomized controlled trials are warranted to assess the potential role of non-caloric caffeine-containing beverages in reducing the risk of obesity and type 2 diabetes.
“Our mendelian randomisation finding suggests that caffeine might, at least in part, explain the inverse association between coffee consumption and risk of type 2 diabetes,” write the researchers.
“Randomised 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,” they conclude.
