Researchers at the University of Eastern Finland found that men who ate more animal protein tended to have lower blood testosterone levels, while those who consumed more plant protein generally had higher concentrations. The study, published in the International Journal of Food Sciences and Nutrition, examined dietary habits and hormone levels across 2,546 male participants.
Study of More Than 2,500 Men Reveals Contrasting Protein Patterns
Data from 2,546 Finnish men aged 42 to 60 residing in the eastern region of the country were evaluated by the investigators. The subjects took part in the ongoing Kuopio Ischaemic Heart Disease Risk Factor Study, which is an investigation managed by the University of Eastern Finland. Over a four-day span from 1984 to 1989, the individuals logged all their food intake, enabling the team to assess their protein sources and nutritional patterns.
Blood samples were collected to measure total testosterone and sex hormone-binding globulin, a protein that regulates circulating testosterone. Individuals with the highest animal protein consumption displayed mean total testosterone levels that were 1.2 nmol/l lower in comparison to those who ingested the least. Plant protein showed the opposite pattern, with men in the highest intake group having testosterone concentrations 1.1 nmol/l higher than those in the lowest group.
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Men with the highest ratio of animal to plant protein had the lowest levels of free testosterone, which is the portion not bound to a blood protein and therefore more readily available to the body, according to Around Prague.
Dairy and Plant Proteins Show Different Testosterone Links
A closer examination of individual protein sources revealed additional differences in male hormone levels. Higher consumption of protein from dairy products was associated with lower concentrations of both total testosterone and sex hormone-binding globulin. Conversely, subjects who derived a greater share of their plant protein from non-cereal items and vegetables generally exhibited elevated total testosterone levels.
Meat protein showed a somewhat different relationship during the analysis. Although greater meat protein intake was linked to lower sex hormone-binding globulin concentrations, researchers did not find a corresponding association with total testosterone levels. As reported by Around Prague, plant-based protein options typically supply greater amounts of fiber, carbohydrates, and unsaturated fatty acids, whereas animal-based alternatives tend to provide higher levels of cholesterol and saturated fat.
Statistical Modeling and Hormone Differences in Finnish Participants
Statistical models of what would happen if a middle-aged man replaced animal protein with plant protein showed no significant link to either total or free testosterone, according to Around Prague. The participants were predominantly from the Caucasian group, meaning the findings may not apply to other population groups, UA.NEWS reported.
“Although the observed differences in testosterone concentrations were statistically significant, they were relatively small. Based on this study, it is not possible to infer whether these differences have implications for health,” said Miika Wynne-Ellis, doctoral researcher at the University of Eastern Finland.
Questions About Dietary Protein and Male Hormone Health
Questions about the University of Eastern Finland study
What ages were the men in the University of Eastern Finland study?
The study analyzed 2,546 men between the ages of 42 and 60 who lived in eastern Finland as part of the Kuopio Ischaemic Heart Disease Risk Factor Study.
How many days did participants record their food intake?
Participants recorded everything they ate over a period of four days between 1984 and 1989 to allow researchers to evaluate their dietary habits.
Where were the study results published?
The findings were published in the International Journal of Food Sciences and Nutrition.
Between 1984 and 1989, participants in the Kuopio Ischaemic Heart Disease Risk Factor Study recorded their dietary habits over four days and provided blood samples.
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