Coffee is consumed around the world every day, and previous research has associated coffee consumption with a reduced risk of diseases such as type 2 diabetes and cardiovascular disease. Scientists still don’t fully understand the biological processes that could explain those connections. Now, new Finnish research suggests that regular coffee consumption is associated with healthier body composition, favorable metabolic markers, and distinct patterns involving sex hormones in men and women.
Researchers at the University of Oulu analyzed data from 2,264 people who were 46 years old and participated in the Northern Finland Birth Cohort of 1966. The team investigated how the participants’ habitual coffee intake was related to circulating metabolites, cardiometabolic risk indicators, and sex hormone levels.
Coffee drinkers had less fat and more muscle
People who consumed more coffee tended to have lower levels of total body fat and visceral fat, along with greater skeletal muscle mass. These differences appeared even though participants with the highest and lowest coffee consumption had a similar body mass index (BMI).
Higher coffee consumption was also associated with lower circulating concentrations of branched-chain amino acids in both men and women. When these biomarkers are chronically elevated they have previously been associated with insulin resistance and an increased risk of developing type 2 diabetes.
Coffee intake was related to different hormonal patterns
Some of the clearest differences appeared among men. Higher coffee consumption was associated with a more favorable glucose-insulin profile, higher levels of total and bioavailable testosterone, and higher concentrations of sex hormone-binding globulin (SHBG). However, free testosterone and free androgen index were modestly lower.
Hormonal associations were less extensive in women. Higher coffee consumption was primarily associated with increased SHBG and lower free androgen measures.
“Millions of people consume coffee every day, but we still know surprisingly little about how it relates to our metabolism and our hormones. What stood out in our findings was a distinctive hormonal signature that did not disappear even after we took into account BMI and lifestyle factors, and several of these associations differ between men and women,” says Luca Verroest, lead author of the study and doctoral researcher at the University of Oulu.
Hormones May Offer Clue to Coffee’s Links to Health
The findings raise the possibility that hormonal pathways may help explain some of the previously observed relationships between coffee consumption and metabolic health. However, because the research was observational, it cannot establish that coffee consumption directly caused any of the biological differences identified in the study.
The environment also makes the research especially relevant. Finland is among the highest coffee-consuming countries in the world, with an average annual consumption of approximately 11.8 kilograms (26 pounds) per person.
The researchers say the results offer a starting point for studies designed to determine whether coffee itself produces these biological changes and, if so, what compounds may be responsible. Scientists are currently investigating these questions using animal models, with the longer-term goal of moving toward human intervention studies.
Additional research will be needed before the findings can be used to shape dietary recommendations.
The study, “Associations of habitual coffee intake with testosterone and cardiometabolic markers: the Northern Finland Birth Cohort 1966 study,” was published in the journal European Journal of Nutrition.