A recent study of middle-aged adults in Finland has linked high daily coffee consumption to lower body fat, increased muscle mass, and significant hormonal differences, particularly in men. Research published in the European Journal of Nutrition analyzed a cohort of over 2,200 individuals, finding that those who drank five or more cups of coffee per day presented a distinct metabolic and hormonal profile compared to those with low or no coffee intake.
The analysis drew from the Northern Finland Birth Cohort 1966, a long-term population study. Researchers examined participants at age 46, correlating their self-reported coffee habits with clinical measurements of body composition, blood pressure, cholesterol, insulin, and sex hormones. While participants who drank more coffee had less fat and more muscle, their Body Mass Index (BMI) was comparable to non-drinkers. The study's authors emphasize that the findings are observational and do not prove that coffee caused these differences.
The hormonal findings were particularly nuanced. Men with high coffee intake showed higher total testosterone but also higher levels of sex hormone-binding globulin (SHBG), resulting in lower levels of biologically active 'free' testosterone. In both men and women, higher coffee consumption was associated with lower levels of certain amino acids linked to insulin resistance. These results add complexity to the growing body of research on coffee's health effects, a topic of significant interest as consumer purchasing decisions are often influenced by wellness trends.