Scientists find how 'obesity gene' makes people fat
By Ben Hirschler
LONDON (Reuters) - Scientists have unraveled how a gene long associated with obesity makes people fat by triggering increased hunger, opening up potential new ways to fight a growing global health problem.
A common variation in the FTO gene affects one in six of the population, making them 70 percent more likely to become obese - but until now experts did not know why.
Using a series of tests, a British-led research team said they had found that people with the variation not only had higher levels of the "hunger hormone" ghrelin in their blood but also increased sensitivity to the chemical in their brains.
"It's a double hit," said Rachel Batterham from University College London, who led the study, which was published in the Journal of Clinical Investigation on Monday.
The discovery follows studies of blood samples from people after meals, combined with functional magnetic resonance imaging of volunteers' brains and cell-based studies looking at ghrelin production at a molecular level.
Batterham said the work provided new insights and possible new leads for treatment, since some experimental drugs are known to suppress ghrelin and could be particularly effective if targeted at patients with the obesity-risk variant of the gene.
Previous research has also shown that ghrelin can be reduced by eating a high-protein diet.
Steve Bloom of Imperial College London, who was not involved in the study, said the FTO gene only explained a small part of the obesity epidemic but the latest discovery was "an important step forward" in unraveling the various factors involved. Continued...