Brown fat cells provide hope for obesity research

Spontaneous human combustion, anyone? Audacious drivel with an interesting side effect.

"Not all fat cells mean weight gain.

National researchers in cell biology have identified proteins that turn normal skin cells into brown fat cells, which use energy to generate heat.

'Energy only gets burned when your heart beats or your muscles walk up a flight of stairs or when you breathe,' said Clay Semenkovich, chief of the division of endocrinology, metabolism and lipid research at the Washington University School of Medicine.

Brown fat cells do not store energy. They burn it without carrying out a function, such as beating the heart or walking, Semenkovich said.

Until recently, scientists believed that only animals and human babies had brown fat cells. But researchers discovered brown fat cells in adults when PET scans showed higher rates of glucose metabolism in patients who had been waiting in cold waiting rooms at their doctors’ offices.

Brown fat evolved to help people and animals in cold environments stay warm, Semenkovich said.

'People were freezing in the waiting rooms, and they were actually turning on brown fat,' he said.

The presence of brown fat cells in human adults carries implications for obesity research.

'People who are overweight have much less active brown fat,' Semenkovich said.

Researchers at Harvard engineered skin cells from mice and humans to become brown fat. This technology requires further research, though, before scientists can test it on humans.

'There’s always a disadvantage to tricking the body into doing things that it probably should not do,' Semenkovich said.

With brown fat, that disadvantage stems from the heat that the cells release. The excess heat could lead to dangerous and possibly deadly fevers in humans."

Oops.