The same brown fat that keeps bears warm during their winter hibernation could be a key player in the connection between exercise and metabolism.
In a new study a team of American researchers discovered a fat molecule which had previously been linked to exposure to cold temperatures surging in the bloodstream after exercise.
According to lead researcher Kristin Stanford brown fat sets itself apart from ordinary white fat in its ability to generate heat. It is also known to be a powerful calorie burner.
In the new research, two study groups underwent blood testing to probe changes in their lipids after bouts of moderate-intensity exercise. The study participants included people of different ages and activity levels. “One lipokine just shot right up to the top,” said Stanford. She found a consistent pattern of increasing levels of a lipokine called 12, 13-diHOME post-exercise, the same fat molecule that had previously been linked to exposure to cold temperatures.
“Before this rediscovery of the role of brown fat, we were focusing our efforts on white adipose tissue – the fat most people think of when they think about obesity and ways to improve weight loss,” Stanford said.
“We know that exercise is great for metabolism, but we don’t fully understand why that is on a cellular level. This study shows that burning of brown fat and this lipid in particular likely play an important role,” said Stanford who works as an assistant professor of physiology and cell biology at the Ohio State University.
“It’s fascinating that rather than burning calories during exercise – which is what occurs with cold exposure – brown fat is functioning to signal the muscle to take up more fatty acids to use as fuel. During exercise, all the different metabolic tissues, surprisingly including fat tissues, ‘talk’ to each other, which enables the muscles to use energy, contract and perform.”
“This shows that these lipokines can be regulated by exercise, and it highlights a new role that brown fat could play in the metabolic benefits of exercise.”Stanford hopes the latest research could lead to the development of new pharmaceuticals to mimic the impact of exercise to boost muscle function, lower blood lipid levels such as triglycerides and burn more energy to assist in the treatment of obesity and type 2 diabetes.