Two research groups have identified the first gene known to suppress obesity and regulate the burning of calories -- a find that could lead the way toward a drug that keeps people trim.
But don't reach for that second jelly doughnut just yet.The gene, known as Mahogany, or the MG gene, was discovered in mice. It is the sixth gene found to be implicated in obesity. But researchers said it is the first discovered to regulate metabolism and the expenditure of energy.
In one of two studies published in Thursday's issue of the journal Nature, scientists at Millennium Pharmaceuticals in Cambridge, Mass., tested groups of mice with normal and mutated MG genes. They fed the mice diets with varying percentages of fat.
Mice with a mutated MG gene did not gain weight regardless of whether they ate a high-fat diet or a low-fat one. Mice with the normal gene gained weight on the high-fat diet.
Researchers said they were optimistic that the gene would play the same role in humans but cautioned that it has been demonstrated only in mice so far. "Mahogany" refers to the animals' brown fur.
And although the findings suggest it plays an important role in diet-related obesity -- which afflicts most of the 54 percent of American adults who are too hefty -- obesity is thought to more than a matter of genetics.
"Obesity is a complex problem for which diet, exercise and biology all are important," said geneticist Craig Warden of the University of California at Davis.
That's one reason why it could be several years before the researchers can transform their discovery into a fat-busting drug.
"I'm pessimistic that we'll ever get that pill that allows us to remain sedentary, eat high-fat diets and stay lean," said University of Colorado obesity researcher James O. Hill. "But that's what Americans want."
Molecular biologist Karen Moore said the findings could show researchers how to develop a drug to control obesity by mimicking the activity of the mutated gene.