Cold temperatures encourage brown fat, study suggests

New research indicates that white fat can turn into brown fat, and vice versa. In particular, lower temperatures could encourage white fat to change into brown fat.
The study, published in the FASEB Journal, could be an important development in how the roles of white and brown fat are understood. White fat is generally considered “unhealthy”, while brown fat is considered “healthy.”
White and brown fat explained
Recent studies have suggested that lean people tend to have more brown fat than overweight people; active brown fat burns white fat. If a reliable method for increasing a person’s brown fat can be developed, it may form an effective treatment for obesity.
The purpose of white fat is to store energy and produce hormones to go into the bloodstream. Small fat cells produce a hormone called adiponecti, which increases the insulin sensitivity of the liver and muscles. The process reduces the risk of developing type 2 diabetes and heart disease. High levels of white fat slow the production of adiponecti, increasing the likelihood of developing the diseases associated with obesity.
The study
The study involved tagging the specific cell populations of mice, then exposing them to cold temperatures. The results suggested that the temperatures caused brown adipocytes (cells that specialise in storing energy as fat) to divide and form new brown adipocytes. In addition, researchers noticed that around 30 per cent of apparently white adipocytes quickly activated the brown adipocyte program after being exposed to cold stress.
James G. Grannema, Ph.D., a researcher for the Centre for Integrative Metabolic and Endocrine Research at the Wayne State University School of Medicine in Detroit, Michigan said, “Our long-term goal is to harness this cellular and metabolic flexibility for the treatment of metabolic disorders linked to dysfunctional fat, such as type 2 diabetes.
The research has yet to be tested on humans. Gerald Weissma, M.D., Editor-in-Chief of the FASEB Journal explained, “If you want to rev up your metabolism, don’t throw out your winter coat just yet. We still need to know if this holds true in humans. What’s more, the important part of this research is that one type of fat can change to another, and that cold triggers cellular mechanisms that lead to the formation of more brown fat. The ‘switch’ that controls what type of fat is created may be a promising drug target for a variety of obesity-related illnesses.”