Coffee linked to healthier body composition and distinct sex hormone changes – study

Higher coffee consumption has been linked to lower body fat, greater muscle mass and differing sex hormone patterns in men and women in a Finnish study.

Researchers found people who drank more coffee had lower levels of total and visceral fat, the fat stored around internal organs, as well as greater skeletal muscle mass.

These associations were seen even though participants had a similar body mass index (BMI), a measure of weight relative to height.

The University of Oulu study analysed data from 2,264 people aged 46 who were part of the Northern Finland Birth Cohort 1966, looking at habitual consumption alongside circulating metabolites, cardiometabolic risk markers and sex hormones.

In both men and women, higher consumption was correlated with lower circulating levels of branched-chain amino acids.

Persistently high levels of these molecules have previously been linked to insulin resistance, when the body responds less effectively to insulin, and a higher risk of type 2 diabetes.

The strongest differences between the sexes were seen in men. Higher consumption was linked to a more favourable glucose and insulin profile, higher total and bioavailable testosterone and increased levels of sex hormone-binding globulin (SHBG).

SHBG is a protein that carries sex hormones such as testosterone through the bloodstream and influences how much hormone is available for the body to use.

At the same time, free testosterone and the free androgen index were modestly lower in men.

Among women, hormone associations were more limited, mainly involving higher SHBG and lower measures of free androgens, a group of hormones that includes testosterone.

Luca Verroest, lead author of the study and doctoral researcher at the University of Oulu, said: “Coffee is consumed by millions of people every day, yet we still know surprisingly little about how it relates to our metabolism and hormones.

“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.”

The researchers said hormonal pathways could partly explain the relationship between consumption and metabolic health.

However, the research was observational, meaning it can identify associations but cannot establish that drinking coffee caused the biological differences seen among participants.

The study is particularly relevant in Finland, one of the world’s highest coffee-consuming countries, where annual consumption averages around 11.8 kilograms per person.

Researchers are now investigating whether coffee itself drives the biological changes and which compounds could be responsible, initially using animal models.

The longer-term aim is to move to human intervention studies, although the researchers said further research would be needed before the findings could be used to inform dietary recommendations.