Men Who Drink More Coffee Show Higher Testosterone Levels, Study Finds

Does Coffee Boost Testosterone? A Large Study Says It’s Complicated

A morning habit shared by billions of people may be tied to men’s hormone levels in a way nobody fully expected. A large study published in European Journal of Nutrition found that men who drank more coffee daily had significantly higher testosterone than men who drank little or none, even after accounting for weight, smoking, activity, and alcohol. Because the study only captured one snapshot in time, it can’t say coffee itself is raising testosterone rather than something else explaining both.

Researchers analyzed data from more than 2,200 middle-aged adults in Finland, the world’s highest coffee-consuming country, as part of the Northern Finland Birth Cohort 1966 study, which has tracked participants since before they were born. All were around 46 years old.

Beyond testosterone, coffee showed up tied to a wider set of body changes too. Both men and women who drank more coffee had lower blood levels of certain amino acids tied to insulin resistance and diabetes risk. Together, the findings suggest regular coffee drinking is tied to a broader hormonal and metabolic pattern scientists are only beginning to map.

Filtered Coffee and Four Drinking Tiers Defined the Study

Participants came from the Northern Finland Birth Cohort 1966, which enrolled nearly all children born in the Oulu and Lapland regions that year. At the 46-year follow-up, 5,832 surviving participants attended clinical exams. After excluding those with missing coffee data and tea drinkers, the final group included 2,264 people, roughly split between men and women.

Filtered coffee was the dominant type. Researchers grouped participants into non-drinkers, low drinkers (one to two cups), moderate drinkers (three to four), and heavy drinkers (five or more). Participants also fasted overnight and gave blood samples measuring body fat, muscle, blood sugar, insulin, cholesterol, blood pressure, and sex hormones.

Heavy Coffee Drinkers Showed Leaner Bodies and a Milder Diabetes Risk Signal

Heavier coffee drinkers stood out on body composition. Weight, waist size, and hip measurements looked nearly identical across all four groups, but people drinking five or more cups a day carried less body fat, less fat around their organs, and more muscle than lighter drinkers. That gap held up statistically, though it comes with an asterisk: men made up a much bigger share of the heavy-drinking group, and men naturally carry different amounts of fat and muscle than women, so some of this may reflect who was in each group rather than coffee itself.

Coffee drinkers of both sexes also had lower blood levels of amino acids tied in prior research to insulin resistance and type 2 diabetes, a pattern stronger in men. This study only measured the amino acids themselves, not whether anyone developed diabetes, but researchers flagged it as worth watching. Men who drank more coffee also showed a healthier-looking blood sugar and insulin picture, based on a simpler statistical check than the model used for the testosterone findings below.

The Testosterone Connection in Men Who Drink More Coffee

Testosterone drove the headline. In men, total testosterone climbed step by step as coffee intake went up, with moderate and heavy drinkers significantly higher than non-drinkers, and heavy drinkers out-ranking everyone else. In the fully adjusted model, each extra daily cup lined up with a 0.29 nmol/L rise in total testosterone, a population-level pattern, not a promise that one more cup moves any individual man’s number. Heavier drinkers also had higher bioavailable testosterone, the portion the body can actually use, and higher levels of a protein called SHBG, a kind of shuttle bus for hormones in the blood.

Here’s where it gets tangled. Heavier coffee drinkers also had lower free testosterone and a lower score on the free androgen index, both measures of how much active hormone is floating around unattached and ready to act. So coffee was tied to more testosterone overall, but less of it in the free-floating form the body draws on moment to moment. Researchers called this a hormone pattern that may matter for metabolic health, stopping well short of calling it a proven benefit. Past research separately links low testosterone and low SHBG to a doubled or greater risk of metabolic syndrome in men, a cluster of conditions that raises the odds of heart disease and diabetes.

In women, the hormonal story was much quieter. Coffee drinking was linked to higher SHBG and lower free testosterone, but showed no connection to total or bioavailable testosterone, and higher SHBG in women has separately been tied to lower diabetes risk.

This Study Can’t Prove Coffee Raises Testosterone

Because this was a cross-sectional study, a snapshot in time rather than one that followed people over years, it can’t prove coffee caused any of this or say which direction the relationship runs. People with naturally higher testosterone might simply drink more coffee, not the other way around. Diet, stress, and menstrual cycle phase weren’t tracked and could be at play, and testosterone was measured only once despite naturally swinging day to day. The Finnish sample also drinks far more coffee than most populations, which may limit how the findings translate elsewhere.

Longer, controlled studies are needed, the authors say, to pin down whether coffee itself drives these changes and which compounds might be responsible. For now, more coffee and more testosterone travel together in this data, but which one leads remains unknown.

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Disclaimer: This article is for informational purposes only and does not constitute medical advice. The study discussed is observational and cannot establish that coffee causes changes in testosterone or any other measure reported. Anyone with questions about hormone health, diet, or caffeine intake should consult a qualified healthcare provider.

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