A Vaccine to Aid Weight Control

Roger Highfield, the Science Editor of the London Daily Telegraph, reports on a credible development that may provide a logical tool in dieting's battle of the bulge ...

An anti-obesity vaccine that significantly slowed weight gain and cut body fat in tests on animals has been recently announced.

Mature male rats that received the jab ate normally yet gained less weight and had less body fat, suggesting that the vaccine directly affects the body's metabolism and energy use.

The vaccine, described today by an American team in the Proceedings of the National Academy of Sciences, may be especially important to stop "yo-yo dieting," the cycle of repeated loss and regain of weight. The vaccine acts against ghrelin, a naturally occurring hormone that helps to regulate energy balance in the body. This approach is called immuno-pharmacotherapy and is also being tested to treat drug addiction.

Prof Kim Janda of the Scripps Research Institute, La Jolla, California, the senior author, said: "To have an impact on appetite and weight gain, ghrelin first has to move from the bloodstream into the brain where, over long periods, it stimulates the retention of a level of stored energy as fat.

"Our study is the first published evidence proving that preventing ghrelin from reaching the central nervous system can produce a desired reduction in weight gain."

Prof Janda told The Daily Telegraph: "We could speed quickly into human trials, maybe in a year, but we are going to be more cautious," referring to the recent trial at Northwick Park Hospital that went wrong.

Dr Eric Zorrilla, lead author of the study, said a vaccine against ghrelin was "particularly compelling in terms of the well-documented problems of human dieting."

"When you diet, the body responds as if it was starving and produces ghrelin to slow down fat metabolism and stimulate eating, changes meant to help retain and regain body fat.

"As a result, many people end up regaining the weight they lost and more once they go off their diets."

According to the World Health Organization, about one billion people worldwide are overweight or obese.