Reaction: Genetic study shows high levels of caffeine in blood could reduce body fat and risk of type 2 diabetes
Previous research has shown that coffee drinking is associated with a lower risk of cardiovascular disease, but most are short-term, observational studies - they describe associations without being able to determine cause and effect. Research published in BMJ Medicine uses another method (Mendelian randomisation) to study potential causal relationships between caffeine levels in plasma and cardiovascular health, using genetic variants in nearly 10,000 people who participated in long-term studies. Higher genetically-predicted caffeine concentrations in plasma were associated with lower body-mass index and fat mass and a lower risk of type 2 diabetes. In addition, the research shows that 43% of the protective effect of caffeine on the risk of type 2 diabetes was influenced by a reduction in body mass index.