A study found that mild stress increases the heat production of brown fat through amplified cortisol. Findings suggest that mild stress can help people lose weight by increasing the brown fat's main function – create body heat by burning calories.
In the study, the participants enrolled five lean, healthy female participants and asked them to solve math problems. In the second activity, the female participants were asked to watch a stress reliever video.
Brown adipose tissue (BAT), which is commonly known as brown fat, burns calories to produce body heat. People whose body mass index (BMI) is low have higher amounts of brown fat.
The team measured the cortisol levels in the women's saliva. Using infrared thermography, the team measured the women's brown fat activity. This process analyzes the skin's temperature changes in areas that overlap main brown fat regions in humans – the neck region.
While math problems didn't provoke a severe stress response in the participants, the anxiety of having to answer a test raised their cortisol levels and increased the brown fat's calorie-burning activity and heat generation.
"This is important as brown fat has a unique capacity to rapidly generate heat and metabolize glucose," said study co-author Professor Michael Symonds from the University of Nottingham's The School of Medicine. Symonds added that the individualized reaction to psychological stress explains the difference in brown fat's activities among people.
Majority of adults have around 50 to 100 grams of brown fat. However, this type of fat's ability to produce heat is 300 times better (per unit mass) compared to any other tissue in the body. This suggests that brown fat can quickly metabolize lipids and glucose.
Symonds added that a further research into the factors that control the brown fat activity can potentially result in better treatments and prevention of diabetes and obesity. The study findings can result in new methods to incorporate mild stress to coax brown fat activity along with other interventions.
"This is likely to contrast with the negative effects of chronic and more severe stress that can contribute to poor metabolic health," said Symonds.
The findings were published in the journal Experimental Physiology.
Photo : Sodanie Chea | Flickr
