Viruses May Be Fattening

Scientists find evidence to suggest a
viral infection may be cause of human
obesity.

January 30, 2006
For years, scientists have wondered whether viruses
should shoulder some responsibility for the wave of
obesity sweeping the planet.
On Monday, a U.S. medical journal released a study
establishing such a link in chickens.

In all of human history, obesity stands alone among
chronic diseases for the rapidity of its spread.
In fact, the pattern of its quick rise looks very much
like that of an infectious disease epidemic.
Six viruses have already been shown to produce
obesity in animals, but University of Wisconsin,
Madison scientists have now shown that a human
virus can cause obesity in chickens, a strong
suggestion that it could make people fat, too.

The findings, which implicated a type of adenovirus,
were released by the American Journal of
Physiology-Regulatory, Integrative and Comparative
Physiology, which published the study.

“The nearly simultaneous increase in the prevalence
of obesity in most countries of the world is difficult
to explain by changes in food intake and exercise
alone, and suggests that adenoviruses could have
contributed,” reads the study.

Potential Vaccine?
With the idea that obesity might be at least in
part caused by a virus comes the theoretical
potential for a highly lucrative vaccine of great
benefit to public health.

About 127 million adults in the United States alone
are overweight, with 60 million of these defined as
obese, according to the American Obesity
Association. The total cost of obesity to the U.S.
economy, in 1998 dollars, may have been as much
as $78.5 billion, according to the CDC.

The problem also is prevalent in the developing
world, where obesity is frequently found
alongside starvation. Worldwide there are more
than 1 billion overweight adults, of whom at least
300 million of them are obese, according to the
World Health Organization.

“There has been an alarming worldwide increase
in the prevalence of obesity in the past 30 years,”
said Richard L. Atkinson, Professor of Medicine
and Nutritional Sciences at the University of
Wisconsin.
The prevalence of obesity increased by 30 percent
between 1980 and 1990, and by 61 percent between
1990 and 2000.

“This increase is the type of pattern that might occur
with a new infectious disease, as has been seen with
the AIDS virus,” Dr. Atkinson added.

Chicken Fat
In the study, scientists inoculated three-week-old
chickens with three types of human adenovirus.
They found that a virus called Ad-37 caused
obesity in chickens even though the birds did
not eat more.

Another adenovirus, Ad-36, has been linked to
obesity in chickens, mice, and primates, and blood
samples from obese people show they are much
more likely than slim people to carry antibodies
for the virus.

“When human twins are discordant for antibodies
to Ad-36 antibodies, the antibody-positive twin
has a higher body mass index,” reads the
journal’s editorial.

The scientists warn that much more research is
required in the field, and suggest the
“daunting task” of testing all 50-odd human
adenoviruses for their role in obesity would be
the first step toward developing a vaccine.

http://www.redherring.com/Article.aspx?a=15525&hed=Viruses+May+Be+Fattening

Does this mean no more exercising?