PDA

View Full Version : Fitness-to-hike issue; obesity caused in part by (potentially curable) VIRUSES?



minnesotasmith
01-30-2006, 08:39
http://www.eurekalert.org/pub_releases/2006-01/aps-coi012506.php

Public release date: 30-Jan-2006
[<SCRIPT language=javascript type=text/javascript><!--document.write('Print Article (javascript:printWindow()) ');// --></SCRIPT> Print Article (javascript:printWindow()) | E-mail Article (http://www.eurekalert.org/emailrelease.php?file=aps-coi012506.php)<SCRIPT language=javascript type=text/javascript><!--document.write(' | Close Window (javascript:window.close())');// --></SCRIPT> | Close Window (javascript:window.close()) ]

Contact: Christine Guilfoy
[email protected] ([email protected])
301-634-7253
American Physiological Society (http://www.the-aps.org/)

Contagious obesity? Identifying the human adenoviruses that may make us fat

Human adenoviruses may cause human obesity, but more research is needed before a screening test and vaccine become reality. Meanwhile, one researcher advises, 'Eat right, exercise, wash your hands'

There is a lot of good advice to help us avoid becoming obese, such as "Eat less," and "Exercise." But here's a new and surprising piece of advice based on a promising area of obesity research: "Wash your hands."


There is accumulating evidence that certain viruses may cause obesity, in essence making obesity contagious, according to Leah D. Whigham, the lead researcher in a new study, "Adipogenic potential of multiple human adenoviruses in vivo and in vitro in animals," in the January issue of the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology published by the American Physiological Society.
The study, by Whigham, Barbara A. Israel and Richard L. Atkinson, of the University of Wisconsin, Madison, found that the human adenovirus Ad-37 causes obesity in chickens. This finding builds on studies that two related viruses, Ad-36 and Ad-5, also cause obesity in animals.

Moreover, Ad-36 has been associated with human obesity, leading researchers to suspect that Ad-37 also may be implicated in human obesity. Whigham said more research is needed to find out if Ad-37 causes obesity in humans. One study was inconclusive, because only a handful of people showed evidence of infection with Ad-37 – not enough people to draw any conclusions, she said. Ad-37, Ad-36 and Ad-5 are part of a family of approximately 50 viruses known as human adenoviruses.
Researchers now must:

identify the viruses that cause human obesity
devise a screening test to identify people who are infected
develop a vaccine
Screening test and vaccine still a long way off
The Whigham et al. study prompted an editorial in the same issue of AJP-Regulatory, Integrative and Comparative Physiology by Frank Greenway, professor in the Department of Clinical Trials, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge.
"If Ad-36 is responsible for a significant portion of human obesity, the logical therapeutic intervention would be to develop a vaccine to prevent future infections," Greenway wrote. "If a vaccine were to be developed, one would want to ensure that all the serotypes of human adenoviruses responsible for human obesity were covered in the vaccine."
"If one could predict the potential of an adenovirus to cause human obesity by using an in vitro assay or even by animal testing, screening of the approximately 50 human adenoviruses might be accelerated, shortening the time required for vaccine formulation," Greenway wrote. "Human antibody prevalence in obese and lean human populations appears to be the only reliable method to screen adenoviruses for their potential to cause obesity in humans at the present time," he noted.

Obesity contagion theory slow to catch on

The notion that viruses can cause obesity has been a contentious one among scientists, Whigham said. And yet, there is evidence that factors other than poor diet or lack of exercise may be at work in the obesity epidemic. "The prevalence of obesity has doubled in adults in the United States in the last 30 years and has tripled in children," the study noted. "With the exception of infectious diseases, no other chronic disease in history has spread so rapidly, and the etiological factors producing this epidemic have not been clearly identified."

"It makes people feel more comfortable to think that obesity stems from lack of control," Whigham said. "It's a big mental leap to think you can catch obesity." However, other diseases once thought to be the product of environmental factors are now known to stem from infectious agents. For example, ulcers were once thought to be the result of stress, but researchers eventually implicated bacteria, H. pylori, as a cause.

"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 suggest that adenoviruses could have contributed," the study said. "The role of adenoviruses in the worldwide epidemic of obesity is a critical question that demands additional research."

Ad-37 third virus implicated in animal obesity

The theory that viruses could play a part in obesity began a few decades ago when Nikhil Dhurandhar, now at Pennington Biomedical Research Center at LSU, noticed that chickens in India infected with the avian adenovirus SMAM-1 had significantly more fat than non-infected chickens. The discovery was intriguing because the explosion of human obesity, even in poor countries, has led to suspicions that overeating and lack of exercise weren't the only culprits in the rapidly widening human girth. Since then, Ad-36 has been found to be more prevalent in obese humans.

In the current study, Whigham et al. attempted to determine which adenoviruses (in addition to Ad-36 and Ad-5) might be associated with obesity in chickens. The animals were separated into four groups and exposed to either Ad-2, Ad-31, or Ad-37. There was also a control group that was not exposed to any of the viruses. The researchers measured food intake and tracked weight over three weeks before ending the experiment and measuring the chickens' visceral fat, total body fat, serum lipids, and viral antibodies.

Chickens inoculated with Ad-37 had much more visceral fat and body fat compared with the chickens infected with Ad-2, Ad-31 or the control group, even though they didn't eat any more. The Ad-37 group was also generally heavier compared to the other three groups, but the difference wasn't great enough to be significant by scientific standards.
The authors concluded that Ad-37 increases obesity in chickens, but Ad-2 and Ad-31 do not. "Ad-37 is the third human adenovirus to increase adiposity in animals, but not all adenoviruses produce obesity," the study concluded.

There is still much to learn about how these viruses work, Whigham said. "There are people and animals that get infected and don't get fat. We don't know why," she said. Among the possibilities: the virus hasn't been in the body long enough to produce the additional fat; or the virus creates a tendency to obesity that must be triggered by overeating, she said.
Mass screening for these viruses is impractical right now because there is no simple blood test available that would quickly identify exposure to a suspect virus, Whigham et al. said. More work is needed to develop such a test, Whigham said.

###

Source, funding and disclosure
"Adipogenic potential of multiple human adenoviruses in vivo and in vitro in animals," by Leah D. Whigham and Richard L. Atkinson of the Departments of Medicine and Nutritional Sciences at the University of Wisconsin, Madison, and Barbara A. Israel of the Department of Pathobiological Sciences, University of Wisconsin, Madison, is in the January issue of the American Journal of Physiology - Regulatory, Integrative and Comparative Physiology published by the American Physiological Society.
Research was supported by grants from the National Institute of Diabetes and Digestive and Kidney Diseases, and the Beers-Murphy Clinical Nutrition Center, University of Wisconsin. Atkinson, now at the Virginia Commonwealth University, owns all shares of Obetech LLC, a company that markets assays to detect infection with human adenovirus-36 and owns patent rights for these assays.

Editor's note: The media may obtain a copy of Whigham et al. by contacting Christine Guilfoy, American Physiological Society, 301-634-7253 or [email protected] ([email protected]).

The American Physiological Society was founded in 1887 to foster basic and applied bioscience. The Bethesda, Maryland-based society has more than 10,000 members and publishes 14 peer-reviewed journals containing almost 4,000 articles annually.
APS provides a wide range of research, educational and career support and programming to further the contributions of physiology to understanding the mechanisms of diseased and healthy states. In May 2004, APS received the Presidential Award for Excellence in Science, Mathematics and Engineering Mentoring (PAESMEM).

Lone Wolf
01-30-2006, 08:45
Fast food drive-thrus and sitting on your fat azz make you obese. Pretty simple.

Mags
01-30-2006, 13:48
More calories in and less exercise = weight gain
Less calories in and more exercise = weight loss

I have to remind myself of this fact every winter. :)

ScottP
01-30-2006, 13:55
simple physics

Energy in+stored energy used=energy out+energy stored

Lilred
01-30-2006, 20:33
A vaccine that stops a virus that causes obesity? Oh please!! LOL Sorry, but less food and exercise is what will work for most people out there. Sounds like another "hopeful" quick fix that someone is going to make a LOT of money off of. The diet pill, drink, patch is a billion dollar industry. This just sounds like another way for doctors to make a buck off of desperate people.

Jack Tarlin
01-30-2006, 20:44
Gotta agree with Lone Wolf on this one.

From observing other people, as well as studying my own present zeppelinesque physique, I think it's clear people tend to be overweight for two reasons:

1. In some cases, it's genetic, and they're fated to have weight problems no matter what they do.

2. In most cases, tho, it's a matter of lifestyle. If you burn up less than you take in, you're going to gain weight. If this concerns you, you need to either take in less, exercise more, or better yet, both.

But sometimes this is easier said than done.

fiddlehead
01-30-2006, 22:09
It's the food choices man! Coming back to the US last year, i was shocked right away with the choices i had when i ate out. Tons of cheese on the pizzas (much more than the Italian pizza I sometimes get here in Phuket, Thailand). Fried shrimp vs. stir fried, Fried everything including french fries with tons of cheese on top is something i hadn't remembered seeing before but saw many times this past year.
So often there are just NO healthy choices when you are eating out. I ate lots of Chinese and cooked a lot and still gained weight back there.
Now i'm back here and it's all good again. every time i go out to eat, it's 95% healthy choices on the menu with fresh crab (that you can actually eat) my favorite.
No wonder most of the American women i saw had fat asses. It's getting to be the norm. Easy to see why.

Twofiddy
01-31-2006, 09:43
Gotta agree with Lone Wolf on this one.

From observing other people, as well as studying my own present zeppelinesque physique...

But sometimes this is easier said than done.

Jack have you been spending time at the AT GYM? or has all your cyber-hiking over the winter buffed you up a little??

Lone Wolf
01-31-2006, 09:47
Jack probably climbs up and down stairs daily at The Five Olde Nugget.:)

minnesotasmith
02-03-2006, 10:14
http://www.comics.com/comics/pearls/archive/pearls-20060201.html

Look at the February 1, 2006 one...:rolleyes:

Sloghound
02-05-2006, 23:25
A leading Jamaican bariatrician, Dr. Addie Posse, has announced her findings.

"All dese Nort' Americans---riding, boob-tubing, and face stuffin' dere way tru life. Id duddn take a Caribbean medical Einstein to solve this myst'ry! Plus, if dey be gotten a virus, dey're gonna feel lisless and won't be watch'n dere Richard Simmons exercise show. Ya, mon".

(With apologies to educated Jamaicans--I had to work with Posse as a last name)

Check out "The Paleo Diet for Athletes"!

bfitz
02-06-2006, 00:17
If you're interested in this obesity, and the related topics of ageing and diabetes read this and start googling the ideas found within...

http://www.drlam.com/opinion/insulin_and_aging.cfm

brz
02-07-2006, 04:37
This is what happens when you don't have a science background. You jump to hysterical conclusions.

Lets try again.

Consider these facts
a.) 1 in 2 Americans are overweight
b.) 1 in 3 American are considered "Obese"
c.) Absolutely NO OTHER COUNTRY ON EARTH has this problem with such magnitude.

Conclusion: Hmm, a 'fat' virus that only attacks 'mericans? Better hope Osama doesn't discover this.