Australian scientists: "brown fat" may help fight obesity

Australian scientists believe " brown fat," a wondrous tissue that burns energy to generate heat, could help people fight obesity, local media reported on Monday. A research team from Sydney's Garvan Institute of Medical Research (GIMR) has worked out how to grow brown fat from stem cells biopsied from adults, raising hopes that one day brown fat could be transplanted in obese people to speed up calories they burn, the Australian Associated Press (AAP) reported. Garvan endocrinologist Paul Lee, who led the research, is optimistic about targeting brown fat as an obesity intervention, commenting "it's a highly metabolically active form of fat, and very exciting that we may be able to stimulate its growth in people." People are born with supplies of brown fat around their neckline to keep them warm as infants, according to scientists at GIMR. Scientists now know that brown fat is present in most, if not all, adults mainly just behind the collarbone. Studies have found that adults with brown fat are slimmer than those without. "Although this is early work, it is a proof of concept study showing that the growth of brown fat cells is possible, using precursor cells taken from adult humans, under appropriate stimulation," Lee said. "Regardless of whether or not someone has lots of or little brown fat, the precursor cells are universally present. Under the appropriate growth factor and hormonal stimulation, the cells all grow and differentiate into mature brown fat cells." However, Lee warned more work was needed. Lee said even if brown fat was transplanted into obese people or drugs developed to stimulate the growth of brown fat, exercise and a healthy diet would still be crucial to aiding weight loss. "So I don't think this is a solution to obesity because there are so many other factors (involved in obesity)," he said. "Despite how efficient brown fat is at burning energy, we would only need a few doughnuts to diminish or negate its benefits." Lee said it would be years before tests could be carried out on brown fat transplants. In the meantime, he is expanding his study to test different ways to grow brown fat. His study, to be printed in the October issue of Endocrinology, has been published in the online edition of the journal.