Discovered: Hunger hormone
2002-03-11 13:57
London - British researchers said on Monday they had isolated a "hunger hormone" that dramatically boosts human food consumption, raising the prospects of new treatments for both the obese and the malnourished.
"There is currently little effective medical treatment for obesity and we are very excited to have taken this step toward a future therapy," said Dr Alison Wren, Research Fellow at Imperial College, London.
Many appetite-controlling mechanisms are in the brain. But Wren said ghrelin, named after the Hindi word for growth, was the first such hormone circulating in the blood to have been isolated.
"I am sure there will be pharmaceutical companies looking at this research. We hope that by targeting ghrelin with specific drugs, it may be possible to therapeutically control hunger."
Fellow researcher, Professor Steve Bloom, Head of the Department of Metabolic Medicine at Hammersmith Hospital, London, said: "The advantages of this kind of therapy may extend beyond the treatment of obese patients and include conditions that induce a dangerous loss of appetite, such as cancer.
"In cases such as this, ghrelin supplements could potentially help to normalise eating patterns."
Scientists have known for some time that the hormone stimulates hunger in rats. Now they have shown that it can also make people so ravenous they eat nearly a third more food than usual.
The findings, published in the Journal of Clinical Endocrinology & Metabolism, follow a study in which five men and four women volunteers were given a dose of ghrelin or a placebo and told to eat as much as they wanted.
One week later, the experiment was repeated, except that those who had been on placebo now received the hormone, and vice versa.
The results revealed that those volunteers who received the hormone consumed an average of 28 per cent more calories than those who received the placebo.
"We were trying to mimic levels of ghrelin after an overnight fast and may have overdone it a bit," Wren told Reuters. But she said other studies also showed significant differences in food consumption at smaller doses.
Other scientists, however, are cautious about the prospects of an eventual therapy. They point out that previous enthusiasm about leptin, which was dubbed the "obesity hormone," turned out to be misplaced and did not lead to a cure for obesity.