2007-08-22 03:41:54
How many reasons do they need ??
Mon Aug 20, 3:09 PM ET
A common virus that causes colds can be a factor in obesity, according to a
study released Monday offering further evidence that a weight problem may be
contagious.
The adenovirus-36 (Ad 36) has already been implicated as the cause of weight
gain in animals, but with this study researchers showed for the first time that
it can also cause humans to pile on the pounds.
The findings could accelerate the development of a vaccine or an antiviral
medication to help fight the battle of the bulge alongside diet and exercise.
"We're not saying that a virus is the only cause of obesity, but this study
provides stronger evidence that some obesity cases may involve viral
infections," said Magdalena Pasarica, an obesity researcher at the Pennington
Biomedical Research Center at Louisiana State University in Baton Rouge.
A previous study found that almost a third of obese people are infected with
the virus compared to around one in 10 of their leaner counterparts.
In laboratory experiments, the Louisana State University researchers found that
the bug appeared to promote the formation of fat cells from stem cells.
The team took adult stem cells from fatty tissue left over from patients who
had undergone liposuction, a procedure to remove fat, and exposed some of it to
Ad-36, leaving the rest untreated.
After a week of growth in tissue culture, most of the virus-infected adult stem
cells developed into fat cells, whereas the untreated cells did not.
It's not clear what drives the transformation, how long the virus lingers in
the human system or whether its fat-enhancing effect continues after the body
has cleared the virus, the researchers said.
A study in animals found that they remained obese up to six months after the
infection had cleared.
The Louisiana State University team is working on further studies to try and
establish why some people with the virus develop obesity while others don't.
"Not all infected people will develop obesity," said Pasarica. "We would
ultimately like to identify the underlying factors that predispose some obese
people to develop this virus and eventually find a way to treat it."
Pasarica presented the results of her study at a meeting of the American
Chemical Society in Boston.