High caffeine levels in the bloodstream could be linked to lower body fat and also reduce the risk of type 2 diabetes. This is according to a 2023 study led by researchers from the Karolinska Institute, the University of Bristol, and Imperial College London.
The findings, published in BMJ Medicine, shed new light on how caffeine influences metabolic health. They suggest that calorie-free caffeinated beverages might be worth exploring as a potential tool. These beverages could help manage obesity and related diseases.
GENETIC CLUES REVEAL CAFFEINE’S METABOLIC IMPACT
The study used data from nearly 10,000 individuals. It applied Mendelian randomization. This is a method that uses genetic variants to assess causal relationships. These relationships are between blood caffeine concentrations, body mass index (BMI), and disease outcomes.
The analysis focused on genetic variants in two genes — CYP1A2 and AHR. They influence how quickly caffeine is metabolized. Individuals with variations linked to slower caffeine metabolism typically have higher plasma caffeine concentrations. These individuals were found to have lower BMI. They also have lower body fat mass.
Importantly, researchers estimated that around 50% of the reduction in type 2 diabetes risk was observed. This reduction could be attributed to caffeine’s effect on body fat.
“Genetically predicted higher plasma caffeine concentrations were associated with lower BMI and whole-body fat mass,” the study reports.
POTENTIAL MECHANISMS: THERMOGENESIS AND FAT OXIDATION
Caffeine’s well-documented effects on metabolism include increased thermogenesis, which is heat production. They also involve fat oxidation, which means burning fat for energy. These effects are likely behind the observed health benefits.
The study did not find a significant link between caffeine levels and cardiovascular diseases such as atrial fibrillation, stroke, or heart failure. This offers some reassurance for those concerned about caffeine’s broader health impacts.
CAUTION ADVISED DESPITE PROMISING INSIGHTS
These results align with earlier research showing caffeine’s role in weight management. It also plays a part in glucose metabolism. However, experts caution that more long-term studies are needed. The current findings rely on genetic analysis, which, while powerful, is not a substitute for randomized controlled trials.
“Randomized controlled trials are warranted. We need to assess whether non-caloric caffeine-containing beverages might play a role. They could potentially reduce the risk of obesity and type 2 diabetes,” said study co-author Benjamin Woolf. He is a genetic epidemiologist at the University of Bristol.
A BREW WITH BENEFITS?
Given the global popularity of caffeine, even modest health effects could have widespread implications. But researchers emphasize its potential side effects should not be overlooked. These include anxiety, sleep disruption, and heart palpitations.
Still, this study marks a significant step in understanding how our genes and metabolism interact with one of the world’s most consumed stimulants — and how that relationship could be leveraged for better health outcomes.
