Coffee drinkers have less fat, more muscle, and surprising hormone differences

Coffee is consumed around the world every day, and earlier research has associated coffee drinking with a reduced risk of conditions including type 2 diabetes and cardiovascular disease. Scientists still do not fully understand the biological processes that might explain those connections. Now, new research from Finland suggests that regular coffee consumption is associated with healthier body composition, favorable metabolic markers, and distinct patterns involving sex hormones in men and women.

Researchers at the University of Oulu analyzed information from 2,264 people who were 46 years old and taking part in the Northern Finland Birth Cohort 1966. The team investigated how participants' usual coffee intake related to circulating metabolites, indicators of cardiometabolic risk, and sex hormone levels.

Coffee Drinkers Had Less Fat and More Muscle

People who consumed more coffee tended to have lower levels of both total body fat and visceral fat, along with greater skeletal muscle mass. These differences appeared even though participants with higher and lower coffee intake had a similar body mass index (BMI).

Higher coffee consumption was also associated with lower circulating concentrations of branched-chain amino acids in both men and women. When chronically elevated, these biomarkers have previously been associated with insulin resistance and a greater risk of developing type 2 diabetes.

Coffee Intake Was Linked to Different Hormone Patterns

Some of the clearest differences appeared among men. Greater coffee consumption was associated with a more favorable glucose-insulin profile, higher levels of total and bioavailable testosterone, and greater concentrations of sex hormone-binding globulin (SHBG). However, free testosterone and the free androgen index were modestly lower.

The hormonal associations were less extensive in women. Higher coffee consumption was mainly associated with increased SHBG and lower measures of free androgens.

"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," says Luca Verroest, lead author of the study and Doctoral Researcher at the University of Oulu.

Hormones Could Offer a Clue to Coffee's Health Links

The findings raise the possibility that hormonal pathways could help explain some of the previously observed relationship between coffee consumption and metabolic health. Because the research was observational, however, it cannot establish that drinking coffee directly caused any of the biological differences identified in the study.

The setting also makes the research especially relevant. Finland ranks among the world's highest coffee-consuming countries, with average annual consumption of approximately 11.8 kilograms (26 pounds) per person.

Researchers say the results offer a starting point for studies designed to determine whether coffee itself produces these biological changes and, if so, which compounds may be responsible. Scientists are currently investigating these questions using animal models, with the longer-term aim of moving toward human intervention studies.

Additional research will be necessary before the findings can be used to shape dietary recommendations.

The study, "Associations of habitual coffee intake with testosterone and cardiometabolic markers: the Northern Finland Birth Cohort 1966 study," was published in the European Journal of Nutrition.

 

Journal Reference:

1. Luca Verroest, Jari Jokelainen, Shalini Choudhary, Jaroslaw Walkowiak, Toni Karhu, Saranya Palaniswamy, Juha Auvinen, Marjo-Riitta Jarvelin, Karl-Heinz Herzig, Ghulam Shere Raza. Associations of habitual coffee intake with testosterone and cardiometabolic markers: the Northern Finland birth cohort 1966 study. European Journal of Nutrition, 2026; 65 (5) DOI: 10.1007/s00394-026-04038-z

Courtesy:

University of Oulu, Finland. "Coffee drinkers have less fat, more muscle, and surprising hormone differences." ScienceDaily. ScienceDaily, 19 August 2026. <www.sciencedaily.com/releases/2026/08/260819041228.htm>. 

 

 

 

This ultrasound treatment may help stop arthritis before it starts

Researchers at The University of Alabama in Huntsville (UAH), part of The University of Alabama System, have identified a promising new use for continuous low-intensity ultrasound that could one day help treat joint injuries and reduce the risk of post-traumatic osteoarthritis. Their findings suggest the non-invasive approach may shift the body's immune response away from long-lasting inflammation and toward tissue repair, offering a potential drug-free strategy for improving healing.

The study, published in the Nature journal Scientific Reports, was led by Dr. Anuradha Subramanian, professor of chemical and materials engineering. It combined biological research conducted by Dr. Shahid Khan during his doctoral studies with computational and statistical analysis developed by Dr. Satyaki Roy, professor of mathematical sciences, along with contributions from graduate student Owen Trippany. The research was funded by the National Institutes of Health through an R01 grant awarded to Subramanian.

How Ultrasound Influences Immune Cells

The team focused on macrophages, specialized immune cells that play a key role in both inflammation and tissue repair, to understand how they respond to continuous low-intensity ultrasound.

"Following injury, the body recruits inflammatory 'defender' macrophages (M1) to clear damaged tissue and healer macrophages (M2) to support repair and recovery," Subramanian explains. "Persistent dominance of defender macrophages can create a prolonged inflammatory environment that contributes to post-traumatic osteoarthritis."

The researchers wanted to determine whether ultrasound could encourage these immune cells to transition from an inflammatory state to one that promotes healing.

"In an 'M1' state, microphages promote inflammation to fight damage or infection, but prolonged M1 activity can also harm healthy tissue," Subramanian notes. "In contrast, 'M2-like' macrophages support tissue repair and recovery. Shifting macrophages toward an M2-like state is important, because it may help reduce chronic inflammation while encouraging healing in damaged joints. Our findings suggest that continuous low-intensity ultrasound may help restore this balance by promoting a more reparative macrophage response."

Roy says chronic inflammation is a major factor in the development of post-traumatic osteoarthritis.

"Post-traumatic osteoarthritis is driven in part by persistent inflammation that limits tissue repair and accelerates joint degeneration," Roy adds. "Our team is interested in continuous low-intensity ultrasound because it offers a non-pharmacological, non-invasive approach that may help regulate immune cell behavior and promote a more reparative healing environment in injured joints."

A More Realistic Model of Joint Injury

To better recreate the conditions inside an injured joint, the researchers relied on fibronectin fragments, molecules generated as damaged tissue breaks down, instead of using only conventional laboratory methods to trigger inflammation. This approach produced a model that more closely reflects the biological environment that develops after a joint injury.

The team also combined transcriptomics, the large-scale study of gene activity, with an advanced computational method known as differential clustering. Rather than analyzing genes one by one, this technique identifies groups of genes whose behavior changes together, providing a broader picture of how immune cells respond to ultrasound treatment.

"This allowed us to study not only which genes changed, but also how groups of genes changed their coordinated behavior in response to ultrasound stimulation," Roy says.

Early Results Show Reduced Inflammation

The researchers found that continuous low-intensity ultrasound lowered biological markers linked to inflammation while increasing markers associated with a more reparative, M2-like macrophage state.

Although the research is still limited to laboratory experiments, the findings suggest that non-drug, non-invasive technologies could eventually be used to influence immune cell behavior and improve healing after joint injuries. The researchers believe the technique could become part of future treatments designed to slow the progression of osteoarthritis and improve recovery after joint trauma.

"The next steps will involve validating these findings in animal models of early post-traumatic osteoarthritis and studying how ultrasound-based modulation affects long-term tissue repair in joint injury settings," Subramanian says.

Journal Reference:

1. Shahid Khan, Owen Trippany, Anuradha Subramanian, Satyaki Roy. Continuous low-intensity ultrasound influences the transcriptomic profile in M1 macrophages by downregulating inflammation and promoting M2-like markers. Scientific Reports, 2026; DOI: 10.1038/s41598-026-53228-6

Courtesy:

The University of Alabama in Hunstville. "This ultrasound treatment may help stop arthritis before it starts." ScienceDaily. ScienceDaily, 12 July 2026. <www.sciencedaily.com/releases/2026/07/260710003521.htm>.