Brown fat in a wider metabolic picture

# Brown fat in a wider metabolic picture OCTOBER 15, 2026 | LONGEVITY SPECIAL People who have active brown fat tend to have healthier blood sugar, cholesterol and heart measurements, and fewer cardiovascular and psychiatric diagnoses, according to a large new study in Nature. The finding is a pattern in patient records. It does not show that brown fat protects health, and it does not show that anyone should take a blood pressure drug to get more of it. We reviewed only the study's abstract; the cell and mouse details below come from press coverage, not the paper. A tissue known for heat production appears here in a much broader set of health associations. Large-scale clinical records can reveal those relationships, although they cannot explain them on their own. The study, published in Nature in 2026, analysed a cohort of 101,243 patients from a large cancer centre. It looked at existing patient data in people, so it can show associations but not cause and effect. Using a machine learning approach, the researchers semi-automatically measured brown fat activity in about 8,700 of those patients. Brown fat is different from the white fat most people think of when they think of body fat. White fat stores energy. Brown fat, formally brown adipose tissue or BAT, uses energy to produce heat. The study's authors note that earlier work linked detectable brown fat in humans to a lower prevalence of cardiometabolic diseases, meaning conditions of the heart and metabolism. What was missing was a full picture of the health conditions tied to it, and a fast way to measure its activity in large numbers of people. This study aimed to fill both gaps. Across all diagnoses, cardiovascular and psychiatric diseases were less prevalent in people with detectable brown fat. Among the patients whose brown fat activity was measured, higher activity was linked to lower odds of cardiometabolic disease and to a healthier distribution of white fat. This was especially true for brown fat in the armpit area, which the abstract calls the axillary depot. People with brown fat also had more favourable blood sugar measures, lipid profiles (blood fats such as cholesterol), inflammatory markers and heart ultrasound readings, according to the study. The psychiatric link is the least familiar part. The abstract reports lower rates of psychiatric disease in people with brown fat. News-Medical, covering a Rockefeller University release, says this included lower rates of anxiety and depression, and describes the link as reported for the first time in this study. First author Nicolás Gómez-Banoy offered one possible explanation in that coverage: "We know that metabolically healthy people tend to have lower incidence of psychiatric diseases, so it could be that having brown fat makes you more metabolically healthy, and this correlates with fewer psychiatric issues." That is a hypothesis. The study does not test it. The drug finding came from the same records. Use of angiotensin receptor blockers, a class of blood pressure medicine, was positively associated with the presence of brown fat. As a proof of concept, the researchers showed that one of these drugs, losartan, increased brown fat cell activity and whole-body energy expenditure. The abstract does not say in which models this was tested. The News-Medical coverage says it was shown in cultured brown fat cells and in healthy mice, which kept a steady body weight. Why this is not a reason to start losartan. The link in patients is an association, so it cannot show that the drug produced the brown fat. Losartan is a prescription medicine given for a medical need. The abstract does not report that taking it improves health through brown fat in people. The coverage also says the authors flagged possible downsides of brown fat for future study, including higher rates of osteoporosis and skin disease. It adds that the SSRI antidepressants were associated with dampened brown fat activity. Readers should not start losartan, any other angiotensin receptor blocker, or any drug or supplement to boost brown fat without talking to their clinician, and should not change a prescribed medicine without talking to their doctor. There are other cautions. The patients were treated at a cancer centre, and they may differ from the wider population. The abstract also gives no size for the associations, so how large the health differences are is not stated there. The authors present the work as a platform for drug repurposing: using existing, well-studied drugs to activate brown fat. In the Rockefeller University release, republished by News-Medical, Gómez-Banoy said losartan's brown fat effects appear to work through different molecular pathways than its blood pressure effects. If so, future treatments might separate the two. Senior author Paul Cohen said in the same release, "This is just a start." What to watch next is whether studies in people can show that switching on brown fat improves health, and whether the other medications the team flagged hold up. The next advance would distinguish a marker of healthier physiology from a way to influence it. That difference determines what the observation can become. Sources: Nature (2026), News-Medical (Rockefeller University release; study in Nature) Nature (2026): https://doi.org/10.1038/s41586-026-11162-7 News-Medical (Rockefeller University release; study in Nature): https://www.news-medical.net/news/20261014/Common-blood-pressure-drug-boosts-brown-adipose-tissue-activity-and-metabolism.aspx ---