A widely prescribed blood pressure medication may help activate brown fat, a specialized energy-burning tissue associated with reduced risks of diabetes, cardiovascular disease and mood disorders, according to a study published Oct. 14 in Nature.
Led by scientists from Rockefeller University and Memorial Sloan Kettering Cancer Center, the investigation examined PET and CT scans from 101,243 cancer patients using machine learning algorithms. The researchers found that individuals with detectable brown adipose tissue had significantly lower rates of type 2 diabetes and heart conditions, as well as lower rates of anxiety and depression, compared to matched controls.
How blood pressure medicine interacts with fat
Unlike common white fat, which stores extra calories, brown fat burns sugar and fatty acids to produce heat. Levels of brown fat generally diminish as people get older, and what remains frequently stays dormant in adults. When researchers looked at patient medication histories, they observed that people taking angiotensin receptor blockers, specifically the drug losartan, were more likely to show detectable brown fat.
To explore that pattern, the team moved to laboratory testing on mouse models and cell cultures. In lab dishes, losartan directly boosted metabolic activity in mature brown adipocytes. In healthy mice, the medication stimulated brown fat, prompting the animals to burn more energy, inhale more oxygen and release more carbon dioxide while maintaining steady weights.
Crucially, researchers determined that the drug stimulates the tissue through cellular mechanisms separate from how it lowers blood pressure. That distinction could pave the way for treatments aimed at non-hypertensive patients.
“The fact that its different effects are mediated by different molecular pathways is advantageous, since it means we could potentially isolate them in future therapies,” endocrinologist Nicolás Gómez-Banoy of Rockefeller University told SciTechDaily. “That way you would be able to stimulate brown fat in people with normal blood pressure.”
Anatomical differences and mental health links
Using artificial intelligence, the investigators measured brown fat across six different anatomical locations, including the neck, chest and underarms. The location of the tissue corresponded to different clinical outcomes. Brown fat located in the axillary, or armpit, region showed the strongest link to lower blood pressure, SciTechDaily reported.
Overall, patients with detectable brown fat displayed superior blood glucose control, better cholesterol measurements and lower levels of systemic inflammation. At the same time, the dataset revealed previously unknown associations, including connections to mental health.
“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,” Gómez-Banoy told SciTechDaily.
The analysis also found that selective serotonin reuptake inhibitors, widely used to treat clinical depression, were correlated with diminished brown fat activity, although the reason for that connection remains unexplained.
Unanswered questions and next steps
Researchers emphasized that the findings show statistical associations rather than direct cause-and-effect in humans. While losartan increased metabolic expenditure in mice, rodents rely far more heavily on brown fat than human beings do, and clinical trials have not demonstrated whether giving the drug to people solely to turn on brown fat provides tangible medical gains.
Furthermore, the imaging database relied exclusively on adult patients undergoing cancer surveillance, more than three-quarters of whom were women. The study also detected unexpected links between brown fat and increased occurrences of osteoporosis and dermatological conditions, indicating that turning on the tissue could bring unintended side effects.
Scientists plan to expand testing to broader populations, investigate the underlying genetics of high brown fat levels, and evaluate whether other common drugs might safely awaken dormant metabolic tissue.
