Health · Medical Research · 6 hrs ago
Higher Animal Protein Intake Linked to Lower Testosterone in Middle-Aged Men
Researchers in Finland studied 2,546 men aged 42 to 60 and found that those reporting more animal protein relative to plant protein had lower total testosterone.
Men who reported more plant protein from sources such as vegetables, legumes and nuts had higher levels of free testosterone.
The findings challenge claims that eating more meat boosts testosterone, a hormone involved in building and maintaining muscle.
The study was observational, based on participants' food reports over four days, so it cannot show that animal protein caused lower testosterone.
The differences were small, and the researchers said their health effects are unknown; the mostly Caucasian group also means the results may not apply to everyone.
Replacing animal protein with plant protein was not significantly linked to either testosterone measure in the researchers' statistical analysis.
Scientists do not yet know whether animal protein affects testosterone or why, and the study does not show that eating more of the hormone is better for health.
A study of 2,546 men aged 42 to 60 found that a higher ratio of animal to plant protein was associated with lower total testosterone.
Men who reported eating the most animal protein relative to plant protein had the lowest free testosterone levels.
Men who ate more plant protein from non-grain sources, such as vegetables, legumes or nuts, had higher free testosterone levels.
The researchers said the observed differences were small and that the study cannot establish whether they affect health.
The observational study did not find that replacing animal protein with plant protein was significantly associated with either total or free testosterone.
- Who
- Researchers from the University of Eastern Finland studied 2,546 men aged 42 to 60.
- What
- A higher animal-to-plant protein ratio was associated with lower total testosterone. More non-grain plant protein was associated with higher free testosterone.
- When
- The article was published on November 9, 2026. The study date is not stated.
- Where
- The University of Eastern Finland conducted the research. The participants’ location is not stated.
- Why
- The researchers examined associations between dietary protein sources and testosterone levels.
Social media proponents of carnivore diets
University of Eastern Finland researchers
Animal protein and testosterone
Social media proponents of carnivore diets
Some social media influencers promote meat-heavy diets as a way to improve testosterone.
University of Eastern Finland researchers
The study found that a higher animal-to-plant protein ratio was associated with lower total testosterone.
Evidence for the claim
Social media proponents of carnivore diets
Carnivore diets are presented as a possible remedy for falling testosterone.
University of Eastern Finland researchers
The researchers said the study was observational and cannot establish whether animal protein decreases testosterone or why.
Study participants carefully reported their dietary intake.
ScienceAlert published an article reporting the study’s findings.
- Study participants
- 2,546 men
- Participants’ ages
- 42 to 60
- Research institution
- University of Eastern Finland
- Dietary reporting period
- Four days
- Study population
- Predominantly Caucasian cohort
What people are saying
Although the observed differences in testosterone concentrations were statistically significant, they were relatively small
The study cannot establish whether these differences have implications for health.
Plant protein sources typically contribute more fiber, carbohydrates, and unsaturated fatty acids, whereas animal protein sources may contribute more saturated fat and cholesterol