The amount of caffeine present in your bloodstream might influence how much body fat you have, which can, in turn, affect your risk for type 2 diabetes and heart diseases.
This comes from a study conducted in 2023 that utilized genetic markers to establish a clearer connection between caffeine levels, body mass index (BMI), and the risk of type 2 diabetes.
Researchers from the Karolinska Institute in Sweden, the University of Bristol, and Imperial College London suggested that calorie-free caffeinated beverages could potentially be examined as a method to lower body fat.
“Higher levels of plasma caffeine, as predicted by genetics, were linked to reduced BMI and overall body fat,” the researchers noted in their study published in March 2023.
They added, “Moreover, higher plasma caffeine levels were connected to a decreased risk of type 2 diabetes. An estimated half of the effect caffeine has on diabetes risk appears to come through lowering BMI.”
The research involved nearly 10,000 participants and focused on genetic variations related to how quickly caffeine is metabolized.
Generally, individuals with genetic variations affecting the genes, particularly CYP1A2 and its regulator gene AHR, tend to process caffeine more slowly. Interestingly, they often consume less caffeine overall.
The approach known as Mendelian randomization was applied to explore causal links between these genetics, health conditions like diabetes, body weight, and lifestyle habits.
While a significant correlation was identified between caffeine levels, BMI, and the risk of type 2 diabetes, no clear link between caffeine in the blood and heart diseases, such as atrial fibrillation, heart failure, or stroke, was found.
Previous research has suggested that a moderate rise in caffeine consumption is associated with improved heart health and lower BMI, adding depth to our understanding of coffee’s effects on health.
It’s important to acknowledge that caffeine’s effects aren’t solely beneficial. Caution is advised when considering the benefits of caffeine intake. Yet, this new study marks a substantial advance in understanding the ideal amount of caffeine.
“Short-term trials have indicated that caffeine consumption can lead to reductions in weight and fat mass, but its long-term effects remain unknown,” the researchers pointed out.
They also mentioned, “Given the global prevalence of caffeine intake, even minor metabolic effects could have significant health repercussions.”
The authors theorized that the observed relationship might be linked to caffeine’s role in boosting thermogenesis (heat production) and fat oxidation (converting fat into energy), both of which are critical for overall metabolism.
This study, while it included a vast sample size, is not without limitations. Mendelian randomization isn’t foolproof, and it’s plausible that other unconsidered factors could be influencing the results. Additional research is necessary to validate these findings.
“Controlled trials are needed to evaluate whether non-caloric caffeine-containing drinks could help mitigate obesity and type 2 diabetes risk,” said genetic epidemiologist Benjamin Woolf from the University of Bristol.
The study has been published in BMJ Medicine.
An earlier version of this article was released in March 2023.
