Do Heavier Coffee Drinkers Have More Testosterone?

According to a new study of 2,264 middle-aged Finns, the short answer is yes for men, at least when it comes to total testosterone. But that's only part of the picture. The same men also had more of a protein that binds testosterone in the blood and slightly less of the free testosterone that circulates unbound. In women, coffee intake showed no link with total testosterone at all.

The study, from the University of Oulu, also found that people in the higher coffee intake groups had less body fat and more muscle than lighter drinkers, despite a similar BMI. Finland is the world's biggest coffee drinker per person, at around 11.8 kg each year according to the European Coffee Report figures cited in the study, so it's a good place to look at what happens when people drink a lot of it. Keep in mind that this is an observational study, so it shows links rather than proof that coffee causes any of these differences. Here's what the research found and why some of it is particularly relevant to anyone brewing filter coffee at home.

What the Researchers Studied

The study was published online on 16 July 2026 in the European Journal of Nutrition. It drew on the Northern Finland Birth Cohort 1966, a long-running population study that enrolled 12,058 children born in the Oulu and Lapland provinces of Finland in 1966, covering 96.3% of births in the region that year. The group has been followed ever since.

For this analysis the researchers used data from the age 46 follow-up, carried out in 2012. They narrowed the group to people who drank only coffee (no tea) or drank neither, leaving 2,264 participants: 2,194 coffee drinkers and 70 non-drinkers. Coffee drinkers were split into three groups: 1 to 2 cups a day (296 people), 3 to 4 cups (822 people) and 5 or more cups (1,076 people). That means nearly half the sample sat in the heaviest drinking group.

Participants were asked to fast for 12 hours overnight and avoid coffee and smoking before their clinical exam. The team measured body composition, blood pressure, blood glucose and insulin (including a two-hour glucose tolerance test), cholesterol, sex hormones and 164 lipid and metabolite measures in the blood.

The Testosterone Finding Is More Complicated Than It Sounds

"More coffee, more testosterone" is the easy headline, but it isn't quite what the study found.

To make sense of it, it helps to know that testosterone travels through the bloodstream in three forms. Some is bound tightly to a protein called sex hormone-binding globulin (SHBG), some is bound loosely to a protein called albumin and a small fraction circulates freely. The free and albumin-bound portions together are called bioavailable testosterone, the share that tissues can readily use. The SHBG-bound portion is held too tightly to be readily available.

In Men

In the fully adjusted analysis, which accounted for BMI, education, smoking, physical activity and alcohol, each extra daily cup of coffee was associated with:

• Higher total testosterone (+0.29 nmol/L per cup)
• Higher bioavailable testosterone (+0.08 nmol/L per cup)
• Higher SHBG (+0.57 nmol/L per cup)
• Lower free testosterone (−0.01 nmol/L per cup) and a lower free androgen index, a ratio of total testosterone to SHBG

So heavier coffee drinkers had more testosterone overall, alongside more SHBG binding it. Lead author Luca Verroest, a doctoral researcher at the University of Oulu, said the hormonal signature stood out because it remained after BMI and lifestyle factors were taken into account.

The researchers suggest this pattern may be relevant to metabolic health, pointing to earlier research in which lower total testosterone and lower SHBG in men were linked to metabolic syndrome, and in which SHBG has been linked to type 2 diabetes risk. They are also clear that these modest associations reflect population-level patterns and are not direct evidence of clinically meaningful hormone changes in any individual.

In Women

The pattern in women was more limited. In the adjusted analysis, higher coffee intake was linked to higher SHBG, lower free testosterone and a lower free androgen index, with no association with total or bioavailable testosterone. This is consistent with earlier research such as the Women's Health Study, where caffeinated coffee was associated with higher SHBG in postmenopausal women. Women who reported polycystic ovary syndrome (PCOS), or didn't report their PCOS status, were excluded from this part of the analysis because PCOS affects androgen levels.

Heavier Coffee Drinkers Had Less Fat at a Similar BMI

The study's other headline result is around body composition. BMI, waist circumference and waist-to-hip ratio were similar across the coffee groups. But the higher intake groups had a lower body fat percentage, less body fat mass, a smaller visceral fat area (fat stored around the internal organs) and more skeletal muscle.

This is a good example of why BMI is a blunt tool. Two people of the same height and weight can carry very different amounts of fat and muscle, and in this study the heavier coffee drinkers tended to sit on the leaner side.

There are some caveats worth knowing. Body composition was measured using bioimpedance analysis, which estimates fat and muscle from how a small electrical current moves through the body. The researchers note this is an indirect method that relies on assumptions about body water and tissue conductivity, so the results should be interpreted cautiously.

The groups also differed in other ways. Men made up 35% of the 1 to 2 cup group but 55% of the 5+ cup group. Heavy drinkers were also more likely to be current smokers and less likely to have a tertiary education. The body composition figures are a straightforward comparison between the coffee groups, while the researchers' adjustments for BMI, education, smoking, physical activity and alcohol were applied in the hormone analysis. So the body composition result is best read as an interesting pattern rather than a clean answer.

What Showed Up in the Blood Work

Beyond hormones, the team found several patterns in the blood work, although most of the correlations were small.

Higher coffee intake was linked to lower levels of branched-chain amino acids (BCAAs) in both men and women, with a broader pattern in men. BCAAs are leucine, isoleucine and valine, and chronically elevated levels in the bloodstream are strongly associated with insulin resistance and type 2 diabetes. The researchers describe the coffee link as a potentially novel finding.

Men who drank more coffee also had lower fasting insulin and better insulin sensitivity. Not everything pointed in the same direction though. In men, higher coffee intake was also correlated with higher levels of several LDL- and IDL-related cholesterol measures. Systolic blood pressure was highest in the 5+ cup group, about 1.6 mmHg higher than the 3 to 4 cup group and about 3.6 mmHg higher than non-drinkers, while diastolic blood pressure didn't differ between groups. The researchers describe these differences as modest.

Why This Is Really a Filter Coffee Study

This is the detail most coverage skips. Of the coffee drinkers who reported what type of coffee they drank, 97.8% drank filtered coffee. Boiled coffee came in at 13.5% and cappuccino at 3.1%, with participants able to select more than one. The researchers also note that Finns typically drink light-roasted coffee, and suggest this may help explain why some of their fatty acid results differ from an earlier trial that used dark-roasted coffee.

Brewing method matters because it changes what ends up in your cup. Coffee contains natural oily compounds called diterpenes, mainly cafestol and kahweol, which can raise LDL cholesterol. A 2025 study led by Uppsala University measured these compounds across brewing methods. Home-brewed, paper-filtered coffee had a median cafestol level of around 12 mg per litre. French press and percolator coffee contained roughly 90 mg per litre, boiled coffee measured 939 mg per litre and some espresso samples reached as high as 2,447 mg per litre.

Because coffee in Finland is predominantly filtered, which substantially reduces diterpene exposure, the Oulu researchers caution against assuming diterpenes explain the cholesterol pattern they saw in men.

The study didn't record what type of filter people used, so there's no way to say exactly how their coffee compares to yours. But if you mostly brew pour over coffee with paper filters, such as a Hario V60, your coffee falls in the same broad category as most of the participants. If you mostly drink French press or espresso, the results may not translate as neatly.

It's also worth knowing what wasn't recorded. The questionnaire didn't define the size of a cup, and there was no information on bean type, roast level, detailed brewing method or whether people added milk or sugar.

What This Study Can't Tell You

The biggest limitation is the study design. It's observational and cross-sectional, meaning it looks at people at a single point in time. It can show that heavier coffee drinkers tended to have a certain profile, but it can't show that coffee caused it, and the researchers note that reverse causation can't be ruled out.

A few other limits the researchers point out:

• Coffee intake was self-reported, with no defined cup size
• Hormones were measured from a single blood sample, and testosterone naturally varies within the same person
• Other factors such as overall diet and stress couldn't be ruled out
• Only 70 people were non-drinkers, and the relatively homogeneous Finnish population may limit how well the findings apply to other coffee cultures

None of this makes the study weak. It's a large population-based cohort with standardised clinical exams and detailed blood testing. It just means the findings need to be tested in longer-term and intervention studies, which is what the authors call for.

So Should You Drink More Coffee?

No, and the researchers aren't suggesting to either. This study can't show that coffee caused any of the differences it found. More broadly, research reviewed in the paper reports the greatest health risk reductions at around three to four cups a day and caffeine intakes of up to 400mg a day haven't been linked to overt adverse effects in healthy adults. Because this study didn't define cup size, there's no way to convert its "five cups" into a caffeine figure.

What the study does offer is some reassurance for people who already enjoy several cups a day. In this group of middle-aged Finns, heavier coffee drinking didn't line up with carrying more body fat. The hormone findings are more nuanced than the headlines suggests and the researchers interpret the pattern in men as potentially favourable for metabolic health while stressing that it needs further study.

At Basic Barista our take is the same as always. Drink the amount of coffee you enjoy, pay attention to how it makes you feel and put your effort into the things that make a real difference to your cup: fresh, good quality coffee beans, the right grind size and a brew method you can repeat consistently. If you like the idea of keeping cafestol low, a paper filter brewer like the V60 is an easy and inexpensive way to do it.

Sources:

• Verroest L, Jokelainen J, Choudhary S, et al. (2026). Associations of habitual coffee intake with testosterone and cardiometabolic markers: the Northern Finland birth cohort 1966 study. European Journal of Nutrition, 65(5), 215.
• University of Oulu (13 August 2026). Study links coffee consumption to metabolic health and sex hormones
• Orrje E, et al. (2025). Cafestol and kahweol concentrations in workplace machine coffee compared with conventional brewing methods. Nutrition, Metabolism and Cardiovascular Diseases, 103933.