Nature study of >100,000 people links active brown fat to lower rates of diabetes, depression and anxiety

On 14 October 2026, Nature published a large study and accompanying news report on active brown fat — metabolically “turned on” fat that burns calories to generate heat — analysed in more than 100,000 people who had undergone PET/CT imaging, typically for cancer care.

Study type and methods

The work, led by physician-scientist Paul Cohen at The Rockefeller University with Memorial Sloan Kettering Cancer Center, is a retrospective observational analysis. Researchers used an artificial-intelligence model to quantify active brown fat from existing scans that inject radioactive glucose and combine PET and CT to highlight metabolically active tissue. Brown fat is typically found around the neck, armpits and chest; unlike white fat, it burns calories for heat.

Main associations reported

According to Nature’s news coverage of Gómez-Banoy et al., people with more active brown fat were less affected by several conditions — including type 2 diabetes, depression and anxiety — than those without, with greater activity linked to greater apparent protection. External experts called the work comprehensive but stressed that a retrospective design cannot prove brown fat causes these benefits.

Limitations (mandatory)

Participants were drawn from a cancer-related imaging cohort, which may not represent the general population. Associations can be confounded by age, body composition, medications, cancer type/treatment and other factors. This is not personal medical advice; lifestyle or medical decisions about body fat require a clinician. DOI: https://doi.org/10.1038/s41586-026-11162-7