ISLAMABAD (Online): Brown fat — which people sometimes refer to as “good” fat — helps the body turn nutrients into energy and generate heat.
Unlike brown fat, another type of fat that scientists call white or yellow fat results from the excessive storage of calories.
Whereas medical experts associate white fat with obesity and metabolic disorders such as diabetes, brown fat may help people stay lean and maintain a healthy body weight.
Some researchers have suggested that prompting the body to turn white fat into brown fat could be a successful way to fight obesity, and studies have focused on specific pathways that could facilitate this fat burning process.
Brown fat metabolizes food into energy by activating the so-called uncoupling protein 1 (UCP1), which exists in the mitochondria of brown adipose tissue.
Previous studies have linked caffeine consumption with weight loss and higher energy expenditure. However, scientists had not yet studied the link between coffee and UCP1 activation, so a team of researchers from the University of Nottingham, United Kingdom, set out to look into this area.
Professor Michael Symonds, from the School of Medicine at the University of Nottingham, is one of the corresponding and lead authors of the study, which appears in the journal Scientific Reports.
Prof. Symonds and team carried out both in vitro and in vivo experiments to see the effect of caffeine on brown fat heat generation, or thermogenesis.
First, they exposed fat-storing cells, or adipocytes — that they derived from stem cells — to caffeine. They noticed that caffeine exposure raised levels of UCP1 and boosted the cells’ metabolism.
These effects “were associated with browning-like structural changes” in mitochondria and lipid droplets.
Secondly, the researchers sought to validate the findings in humans. Using a thermal imaging technique, they located the brown fat reserves in the body and evaluated their heat-generating abilities.
“From our previous work,” explains Prof. Symonds, “we knew that brown fat is mainly located in the neck region, so we were able to image someone straight after they had a drink to see if the brown fat got hotter.”