Why body fat might hold key to living longer, healthier lives

Brown fat transplant in mouse model shows rapid results — What this means for human aging

NEWARK, N.J. — What if the key to a healthier you is hiding in plain sight? It’s not a hormone, vitamin, or miracle drug; it’s a special type of fat tissue. Most of us wage war against unwanted body fat. However, researchers at Rutgers New Jersey Medical School have found compelling evidence that brown fat, a distinct variety that actually burns calories rather than storing them, could be the key to better exercise performance and healthier aging.

This remarkable tissue differs dramatically from the typical white fat that accumulates around our waistlines. Brown fat is packed with mitochondria, which are tiny cellular power plants that generate heat instead of storing energy. These mitochondria give the tissue its distinctive dark color and unique metabolic properties. While babies are born with significant amounts of brown fat to help regulate their body temperature, adults retain smaller deposits, primarily around their neck and shoulders.

Through a comprehensive research perspective published in Aging-US, scientists have synthesized evidence suggesting this specialized fat tissue could help protect against a range of health challenges, from obesity and diabetes to cardiovascular disease. Building on their previous discoveries, the research team, led by Dorothy E. Vatner and colleagues, has consolidated findings about a particular strain of mice lacking a protein called RGS14. These mice, studied in groups of 30-40 animals per experiment, have consistently shown increased longevity compared to normal mice.

Historically, scientists have focused on how exercise affects brown fat, with most studies showing that physical activity can increase brown fat density and activation. However, this research highlights a different angle: how brown fat itself can directly enhance exercise performance, an area that has received surprisingly little attention.

The RGS14-deficient mice demonstrated several intriguing characteristics when tested on specially designed mouse treadmills. They ran significantly longer distances and performed more work before exhaustion compared to normal mice. More remarkably, their physical appearance remained notably more youthful as they aged, maintaining better fur quality and muscle mass than typical older mice.

The research team examined one experiment that involved transplanting brown fat from these long-lived mice into normal mice. The recipients showed enhanced exercise performance within just three days of the transplant. For comparison, when normal mice received brown fat from other normal mice, it took eight weeks to see similar improvements in exercise capacity. This dramatic difference in timing suggests that the modified brown fat possesses unique properties that can rapidly influence whole-body metabolism.

Sophisticated imaging techniques to measure blood flow in the mice’s leg muscles revealed that the transplanted brown fat promoted the growth of new blood vessels in muscle tissue, essentially upgrading the body’s oxygen delivery system. This improved circulation, combined with brown fat’s ability to reduce cellular stress, may help explain its broad benefits for metabolic health and aging.

“In view of the ability of BAT to mediate healthful longevity and enhance exercise performance, it is likely that a pharmaceutical analog of BAT will become a novel therapeutic modality,” study authors write.

Such treatments could potentially help maintain healthy energy levels, support weight management, and promote cardiovascular health. For an aging global population facing increasing health challenges, these findings suggest new therapeutic approaches. While current research remains in the early stages and primarily in animal models, understanding how enhanced brown fat achieves these effects could lead to innovative treatments that help older adults maintain more active lives while reducing their risk of chronic age-related conditions.