Researchers have identified the role of a gene that may help explain why some of us over-eat and become obese.
The gene, known as GAD2, is shown to play an appetite-stimulating role according to a study published in this month's Public Library of Science Biology. One form of GAD2 is strongly-associated with obese people.
GAD2 speeds up production of a neurotransmitter in the brain called GABA. When GABA interacts with another molecule named neuropeptide Y in a specific area of the brain, we are stimulated to eat.
The researchers believe that people who carry a more active form of the GAD2 gene build up a larger than normal quantity of GABA, which in turn drives the stimulus to eat more than normal.
The study showed those carrying a GAD2 allele that increases the risk of obesity were significantly more likely to experience an inability to control their food intake and perceive higher levels of hunger.
Professor Philippe Froguel, senior author of the research, from London's Imperial College and Hammersmith Hospital, carried out the research while at the Institut Pasteur de Lille. Froguel stated:
"The discovery that this one gene plays a role in determining whether someone is likely to over-eat could be crucial in understanding the continued rise in obesity rates around the world.
"Genetic factors alone can not explain the rapid rise in obesity rates, but they may provide clues to preventative and therapeutic approaches that will ease the health burden associated with obesity."
Interestingly, one form of GAD2 was found to be protective against obesity, while another increased the risk of obesity. A group of normal weight French study participants had a higher frequency of the protective form of the gene. (Obesity is three to five times less prevalent in France than in the USA.)
What does this discovery mean to the future of obesity treatment? Froguel suggests a definitive obesity-risk test (and as a result, preemptive treatment) could be in store:
"Having identified this gene, it may be possible to develop a screening to identify those who may be at risk of becoming obese later in life, and take effective preventative measures."
This story includes content adapted from a news release by Imperial College.
Originally Published: October 7, 2003
Last Updated: November 8, 2005
