Active brown fat linked to lower risk of heart disease, diabetes and depression

A study of more than 100,000 people found that measurable brown fat was associated with lower rates of serious metabolic, cardiovascular and psychiatric conditions, including among people who were overweight or obese.

People with active brown fat appear to face a markedly lower risk of a range of serious illnesses, including type 2 diabetes, high blood pressure, heart failure and some psychiatric conditions, according to research highlighted by the National Institutes of Health and reported by The Independent. The findings add to growing evidence that this specialised tissue may do far more than help the body stay warm.

Brown fat, which sits around the neck, chest and armpits, works differently from white fat. Rather than storing excess energy, it burns sugar and fatty acids from the bloodstream, helping the body use calories more efficiently. Scientists have long known that the tissue is important in newborns, but it was once thought to disappear after infancy until later research showed that adults can still carry it.

The study, described by NIH as the largest of its kind, examined more than 100,000 people and found that those with measurable brown fat were less likely to have type 2 diabetes, cardiovascular disease, heart failure or high blood pressure. That protective association remained visible even in participants who were overweight or obese, suggesting the tissue may help buffer some of the health risks linked to excess body weight.

Researchers also reported an unexpected link with mental health. People with active brown fat were less likely to be diagnosed with depression and anxiety, although the biological reason for that connection remains unclear. Dr Nicolás Gómez-Banoy, a physician-scientist at The Rockefeller University, said one possible explanation is that people with brown fat may simply have a healthier metabolic profile overall, which could in turn be associated with fewer psychiatric problems.

The work does not prove that brown fat directly prevents disease, because it was retrospective and cannot establish cause and effect. Irfan Lodhi, a molecular biologist at Washington University in St Louis, said more research is needed to determine whether the tissue itself is driving the benefits, but called the findings “very interesting and surprising”. Scientists are also exploring ways to increase brown fat activity, including cold exposure and drug repurposing, after the study suggested that the blood pressure medicine losartan may boost brown fat in cell and animal experiments.