Exposure to cold temperatures increases levels of a newly discovered protein, called transcription factor Zfp516, which is critical for the formation of brown fat, the type of fat in our bodies that generates heat, according to researchers at the University of California, Berkeley. Researchers also found that with extended exposure to chilly air, Zfp516 protein also helps the more abundant white fat in our bodies, the kind that stores excess energy, become more similar to brown fat in its ability to burn energy.
Brown fat has relatively high levels of mitochondria, the cell's power station. In humans, brown fat was thought to be present only in infants, but stores of it were recently discovered in adults around vital organs like the heart, brain, neck and spinal cord.
Mice studies revealed that rodents with boosted levels of the Zfp516 protein gained 30 percent less weight than control mice when both groups were fed a high-fat diet.
Hei Sook Sul, UC Berkeley professor of nutritional science and toxicology, said, "Knowing which proteins regulate brown fat is significant because brown fat is not only important for thermogenesis, but there is evidence that brown fat may also affect metabolism and insulin resistance. If one can somehow increase levels of this protein through drugs, they could have more brown fat, and could possibly lose more weight even if eating the same amount of food."
The study appears online in the journal Molecular Cell.