Scientists find how 'obesity gene' makes people fat

LONDON Mon Jul 15, 2013 2:49pm EDT

A man sits on a bench in central London, September 23, 2009. REUTERS/Toby Melville

A man sits on a bench in central London, September 23, 2009.

Credit: Reuters/Toby Melville

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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.

The prevalence of obesity is increasing worldwide at an alarming rate and both developed and developing countries are affected. Obesity is a major risk factor for diabetes, heart disease and certain cancers.

At least 2.8 million adults die each year as a result of being overweight or obese and more than 40 million children under the age of five were overweight in 2011, according to the World Health Organization.

Developing effective obesity drugs has been a challenge for drugmakers, although some new medicines are now coming through.

After a gap of more than a decade, two new obesity drugs - Vivus Inc's Qsymia and Arena Pharmaceuticals Inc's Belviq - were approved by the U.S. Food and Drug Administration last year.

Belviq's launch was delayed, however, pending a final classification on its risk of abuse and Qsymia's sales have been disappointing, triggering fierce criticism from Vivus's largest shareholder.

(Editing by Sophie Walker)

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Comments (12)
JonandFlo wrote:
I suppose the scientists will find multiple factors which may contribute to the epidemic of obesity which has spread through western civilization. The single largest component of the epidemic is behavior; being even minimally aware of basic nutrition and simple concepts like “eating more calories than I burn will cause weight gain”. People are responsible for the choices they make and they generally bear the consequences of this choice. These genes were there for centuries but this epidemic is new. We live in a world where people have been absolved of the daily struggle to survive and they have nearly unfettered access to food; both healthy foods and unhealth ones. Real exercise is purely optional. We no longer need to toil all day long to meet basic needs like food and shelter. Heck, you don’t need to toil at all if you’re willing to accept government hand-outs and snap cards.

Jul 15, 2013 1:15pm EDT  --  Report as abuse
andres636 wrote:
Obesity is a modern disease, our way of eating, I wonder why indigenous tribes on every continent did not suffer from these symptoms, indeed there is a gene, but this is I think our way of life, we should not give more excuses overweight people have to encourage good nutrition and sport (the third of the U.S. population is overweight, if this is considered a serious disease pandemic.
http://fajaspieldeangel.com/6-fajas-postquirurgica

Jul 15, 2013 3:46pm EDT  --  Report as abuse
nevenera wrote:
Actually most people don’t die from being overweight, more and more research is showing that the negative effects of being overweight are rather over stated, from studies showing that if you are overweight not only do you not have a greater chance of dying, but you actually have a slightly better chance of living longer, to other studies showing that shedding weight does not decrease chances of dying from heart disease, or diabetes. That in addition to more research showing that if you have serious illness your chances of survival are greater if you are a little overweight.
Increased chances of dying only show up if you are obese and even then the results are not spectacular.
What kills people is being unfit, smoking, having an unhealthy diet not exercising etc, but again looks can be deceiving, exercise alone does not automatically decrease weight even if you are not massively overeating, it does however make you fitter, so it is entirely possible to be larger (overweight) and fitter, if you are exercising regularly than someone who looks is thinner but smokes and/or does not exercise.
It is time to focus on fitness, lowering stress and healthy eating rather than on the physical size of the person. That tends to lead to judgment and prejudice rather than in actual health benefits.

Both people who have written below me are ignoring large and increasing amounts of research that shows that how large a person is has little to do with will power, laziness or being unaware of what to eat, but rather a complex mix of genetics, diet, economic advantage, stress and the ability or lack thereof of being able to exercise.

More importantly how large a person is (unless you are talking obesity) is not a clear indication of how fit they are. Fitness and lowered stress is what saves lives, not being a size zero which incidentally is often just as unhealthy and leads to as short a life as being obese

Jul 15, 2013 4:51pm EDT  --  Report as abuse
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