Key Takeaway:
- Coffee was linked to leaner body composition, including lower total and visceral fat and greater skeletal muscle mass.
- Higher coffee intake was associated with sex-specific hormone patterns, with stronger effects observed in men.
- The study found associations, not causation; further research is needed to determine whether coffee directly causes these metabolic and hormonal changes.
A Finnish study found habitual coffee consumption was associated with lower body and visceral fat, greater skeletal muscle mass, and sex-specific hormone patterns among 2,264 adults, researchers said.
Researchers find leaner profiles among coffee drinkers
Researchers at the University of Oulu analyzed participants from the Northern Finland Birth Cohort 1966, all aged 46, to examine links between habitual coffee consumption, circulating metabolites, cardiometabolic markers and sex hormones.
Participants who reported higher coffee consumption had lower total and visceral fat and greater skeletal muscle mass than those who drank less coffee, despite having similar body mass indexes.
In both men and women, higher coffee consumption was also associated with lower circulating levels of branched-chain amino acids. Persistently elevated levels of these amino acids have been linked with insulin resistance and a higher risk of type 2 diabetes.
The findings add to previous research associating coffee consumption with a lower risk of some metabolic and cardiovascular conditions, although the biological mechanisms behind those relationships remain uncertain.
Hormone associations differ between men and women
The strongest sex-specific associations appeared among men. Higher coffee consumption was associated with a more favorable glucose-insulin profile, higher total and bioavailable testosterone, and higher concentrations of sex hormone-binding globulin, or SHBG.
At the same time, men who consumed more coffee had modestly lower free testosterone and free androgen index measurements.
Among women, the hormonal associations were less pronounced. Higher coffee consumption was mainly associated with increased SHBG and lower measures of free androgens.
“Coffee is consumed by millions of people every day, yet we still know surprisingly little about how it relates to our metabolism and hormones,” said Luca Verroest, the study’s lead author and a doctoral researcher at the University of Oulu.
“What stood out in our findings was a distinct hormonal signature that didn’t disappear even after we took into account BMI and lifestyle factors, with several of these associations differing between men and women,” Verroest said.
Researchers say cause and effect remains unclear
The researchers said the hormonal findings could help explain some of the relationship between coffee consumption and metabolic health. However, because the study was observational, it cannot establish that drinking coffee directly caused the differences.
Finland provides a particularly relevant setting because it is among the world’s highest coffee-consuming countries. Annual consumption there averages about 11.8 kilograms, or 26 pounds, per person.
The findings, published in the European Journal of Nutrition, provide a basis for further research into whether coffee itself causes the observed biological changes and which compounds may be responsible.
Those questions are being studied in animal models, with researchers ultimately aiming to conduct human intervention studies. More evidence will be needed before the findings can support changes to dietary recommendations.
