Have you ever heard of BAT? Brown adipose tissue?
There exists two forms of fat in the human body: white fat and brown fat. The Scientific American shares that white fat cells store energy in the form of a single large, oily droplet that is otherwise relatively immobile. On the other hand, brown fat cells contain many smaller droplets, as well as energy machines known as mitochondria. Only in recent years have researchers found ways to convert white fat to brown fat. Having more active brown fat present can improve insulin sensitivity to help banish type 2 diabetes and heighten the body’s metabolism to reduce body weight.
Amongst multiple research studies, it is unanimous that lower temperatures force the body to induce thermogenesis, the heat generation that increases your body’s core temperature in order to bring it to homeostasis. When this takes place, white fat can then act like brown fat, otherwise called “beige” fat.
Luckily, these temperatures do not have to be low enough to cause muscle quivering. In 2013, Japanese researchers had 12 young men with lower than average brown fat amounts to sit in a 63 degree Fairenheit room for two hours a day for six weeks. After six weeks, those 12 men were burning an extra 289 calories and PET-CT scans verified the heightened quantity of brown fat cells. They believe that exposure to these colder temperatures over six weeks increased the activity of a gene named UCP1, which seems to guide the conversion of white fat into beige fat. They also understand that exercise helps to increase UCP1 in conjunction with a hormone called irisin that helps convert white fat to beige fat.
A study supported by the National Institute of Health (NIH) in 2014 had 5 healthy men reside in a clinical research unit for 4 months. They would do their normal daily activities during get day then return to their private room for at least 10 hours each night. The temperature of the room was set to 24 °C (75 °F) during the first month, 19 °C (66 °F) the second month, 24 °C again for the third month, and 27 °C (81 °F) the fourth and last month. Each month, the men underwent extensive evaluation, including energy expenditure testing, muscle and fat biopsies, and PET/CT scanning of an area of the neck and upper back region to measure brown fat volume and activity.
After a month of exposure to 19 °C (66 °F), the participants showed a 42% increase in brown fat volume and a 10% increase in fat metabolic activity. During the following month of neutral temperature, these alterations returned to near baseline, and then completely reversed during the month of exposure to 27 °C (81 °F). All the changes occurred independently of seasonal changes.The increase in brown fat following cold exposure was accompanied by improved insulin sensitivity after a meal during which volunteers were exposed to mild cold. The extended exposure to mild cold also resulted in significant changes in metabolic hormones such as leptin and adiponectin.
Yu Hua Tseng, Ph.D., the Principal Investigator in the Section on Integrative Physiology and Metabolism at Joslin Diabetes Center, says that “brown fat is a natural defense system for obesity, diabetes and related diseases or conditions.” Because of the supporting research, the idea of activating brown fat as a way to combust this excess energy is now an attractive area of research for developing new treatments to help combat obesity and various metabolic diseases. Increasing your metabolic baseline by activating brown fat could be the key to combating such diseases or conditions.
Imagine this: exercise while being exposed to colder temperatures. George King, M.D., Chief Scientific Officer at Joslin Diabetes Center, recommend combining these known brown-fat activators by working out in the cold to get the maximum benefit. By doing so, you’d be revving up your conversion of white to beige fat, in turn burning more calories and improving insulin sensitivity!
Coral A.J. Gibson