Imagine one day doctors handing out prescriptions to obesity patients. Take a pill a day, and your bad fat turns into good fat without having to get off your couch. Researchers from Harvard University believe they’re on their way to making that reality and are calling their discovery "the first step toward a pill that can replace the treadmill." They published the study in the journal Nature Cell Biology.

"You're constantly replenishing your fat tissue," the study’s coauthor Chad Cowan, from the Harvard Stem Cell Institute (HSCI) said in a press release. "If you were on a medication to convert the cells, each new fat cell would be more metabolically active and would convert to brown fat over time." The system they’ve created will take two compounds from human stems cells that can turn bad white fat into good brown fat, ultimately reducing the risk of developing type 2 diabetes, cardiovascular disease, and high blood pressure.

White 'Bad' vs. Brown 'Good' Fat

White fat is the enemy. It serves as an energy reservoir, and plays a major role in the development of obesity, type 2 diabetes, heart disease, and insulin resistance. Conversely, brown fat's purpose is to burn calories in order to generate heat. Individuals who are younger or in shape have higher levels of brown fat, which also helps balance their blood sugar levels. Exercise converts the white fat into brown fat, and now that Harvard scientists have located the two molecules responsible for the conversion, they’re trying to control them.

"We found these two compounds by screening a library of about 1,000 compounds," Cowan said. "We know that if we have access to the typical pharmaceutical company library of 1.5 to two million compounds, we will find others. We expect to have results fairly soon. The compounds appear to work the same way in mice, but we don't know what the long-term metabolic or immune system effects are.”

When they removed the molecules, the conversion from white to brown fat went away. The same was true for the opposite approach. When researchers added more of the conversion molecules, it increased the amount of white fat turned to brown. It took the team three or four years to perfect the protocol process of going from white to brown, Cowan said. They began working with brown fat over seven years ago, it was just a matter of time before they figured out a safe way to make the switch.

"This is the kind of thing we expected the formation of HSCI," Cowan said. "The good news/bad news is that science is slow. Just establishing proof of concept takes an enormous amount of time. We thought that working with stem cells would lead to the discovery of new drugs and therapies, and now it's really starting to happen. A decade of hard basic scientific work is paying off."

Source: Cowan CA, Moisan A, Lee YK, Zhang JD, Hudak CS, and Meyer CA, et al. White-to-brown metabolic conversion of human adipocytes by JAK inhibition. Nature Cell Biology. 2014.