Building Brown Fat

These are brown fat cells chock-full of mitochondria (magenta) – a characteristic feature of these highly metabolically active cells. Unlike white fat cells, brown fat cells are considered the 'healthy' type because they burn rather than store energy, helping to keep our bodies warm in the process. People with a high proportion of brown fat typically have better cardiovascular and metabolic health but, for people with less, there’s also hope. Scientists have found a way to make more. A study of 100,000 patients revealed that those taking the blood pressure medicine losartan were likely to have more brown fat than those not on the medication. And, in vitro studies confirm the drug boosts these cells. Importantly, losartan’s brown-fat enhancing mechanism uses a completely different molecular pathway to that of its blood pressure lowering activity, meaning it may be possible to create brown-fat building medications for people with normal blood pressure.

Written by Ruth Williams

Ruth Williams

Writer

Ruth is a freelance science journalist based in the US. She's a regular correspondent for The Scientist, and her work has appeared in The Lancet, Nature, Scientific American Mind, BBC Focus and elsewhere. Twitter @rooph

Website

• Image from work by Nicolás Gómez-Banoy and colleagues
• Weslie R. and William H. Janeway Laboratory of Molecular Metabolism at The Rockefeller University, New York, NY, USA
• Image copyright held by the original authors – 'image may only be used to illustrate research described'
• Research published in Nature, October 2026