That’s the hormone that regulates hunger and decreases the body’s ability to burn fat–and it may hold the key to helping those who are too fat or too thin. But, warns the doctor who led the research, there’s still a long way to go. “I think it’s premature to say that ghrelin is going to, by itself, be a magic bullet that will allow us to turn around the tide of obesity that’s sweeping across the world,” says Seattle endocrinologist David E. Cummings.
The findings of Cummings’s team-published this week in the New England Journal of Medicine–has raised hopes of substantial progress in treating both obesity and eating disorders like anorexia. And while doctors say a cure is not yet in sight, Cummings believes an experimental ghrelin blocker could be developed within a year. “We will be working on ghrelin for the foreseeable future,” he says. “The pace of insights into [the hormone] are likely to be lightning fast because many people are involved in the study.”
Cummings and his team are not the first to study ghrelin, which was described and named by Japanese researchers back in 1999 and has since been the subject of numerous papers. But the University of Washington group is the first to compare its levels in dieters and those who have had gastric-bypass stomach surgery. Their tests on 28 volunteers found that ghrelin levels invariably rise before a meal and drop afterward. But the levels of hunger-causing ghrelin rose markedly among the obese subjects after they lost weight through dieting, suggesting one reason dieters often hungrily eat back their lost weight.
Bypass patients who had their stomach partially sealed off, however, had unusually low ghrelin levels–a possible explanation for the greater-than-expected long-term weight loss among those who have the surgery.
For the moment, though, the ghrelin findings may hold out more hope for those who need to gain weight because of conditions like AIDS, cancer or anorexia. “The part of the body that receives the ghrelin signal is turned on much more easily than it’s turned off,” says Cummings. “If you think about it, this is a hunger stimulant. To have something with potency that can actually stimulate food intake in those people [who need to gain weight] would be a terrific medical advance,” he says.
Obesity, too, is harder to treat because it does not have a simple cause. “The treatment of obesity is going to require a cocktail of medications,” says Mitchell S. Roslin, chief of obesity surgery at New York’s Lenox Hill Hospital. “The magic bullet is not going to be simple because obesity is so complex.” Roslin believes the study will make doctors realize “that we need to rethink what we consider obesity. We have begun to recognize obesity as a serious disease,” he told NEWSWEEK. “We’re numerous years away [from a cure], but moving at a faster pace.”
For those who can’t wait that long, California dietitian Jo Ann Hattner offers more conventional advice. Extreme eating programs like low-carb diets are out, she says, because they don’t allow long-term lifestyle changes. “That’s the kind of diet that you will eventually gravitate back toward eating carbohydrates,” says Hattner, a spokesman for the American Dietetic Association. “There is also a lack of maintaining average-size portions. People are often eating the right things, but overeating them. There’s much more to weight management than we think.”
