Sept. 20, 2010 -- Could a virus be contributing to the skyrocketing rates of childhood obesity?
It's possible, according to new research in the journal Pediatrics. Infection with adenovirus 36 (AD36) -- a virus associated with the common cold -- may actually play a role in childhood obesity. The new study shows that obese kids are more likely to test positive for antibodies to this virus than their thinner counterparts.
Some research has linked viral infections to obesity, and AD36 is a possible culprit because animal studies have shown that this virus increases body fat. The nature of this link is not yet understood. The virus could cause weight gain, or perhaps, those who are overweight or obese may be more susceptible to AD36 infection.
Fully 17% of U.S. children are now obese, according to information cited in the new study. As a result, children are developing problems associated with obesity such as high blood pressure and diabetes that were previously primarily seen in adults.
Putting a dent in the childhood obesity epidemic is on everyone's radar including that of First Lady Michelle Obama. The White House Task Force on Childhood Obesity aims to reduce childhood obesity to 5% by 2030.
Other factors -- including unhealthy diets and lack of exercise -- also increase the risk for childhood obesity, but infection could also be part of the story.
Obese Kids More Likely to Test Positive for AD36 Virus
In the new study of 124 children with an average age of 13.6 years, 54% of children were obese and 46% were not. Researchers tested their blood for antibodies to the AD36 virus. Antibodies are produced by the body in response to infection.
Overall, 15% of these kids tested positive for antibodies to the AD36 virus. The majority of those who tested positive were obese, the study showed. Specifically, 22% of obese children had antibodies to this virus, compared with 7% of non-obese kids. Those kids who tested positive for antibodies to AD36 weighed about 35 pounds more on average than the children who tested negative.
"These data support an association between the presence of AD36-specific antibodies and obesity in children," conclude researchers from the University of California at San Diego."If a cause-and-effect relationship is established, it would have considerable implications for the prevention and treatment of childhood obesity."
In an email to WebMD, study researcher Jeffrey Schwimmer, MD, associate professor of pediatrics at the University of California, San Diego says, “In the United States, of all obese children, every 1 percent equals approximately 100,000 children. We found evidence of adenovirus-36 infection in roughly 1 of every 7 children in this study. And most children with evidence of the infection were obese. Large studies would be needed to determine how big a role could be attributed to any given cause, but the possibility exists that adenovirus-36 could be relevant for a large number of children.”
Can a Vaccine Prevent Obesity?
Nikhil V. Dhurandhar, PhD, an associate professor and the chief of the infection and obesity lab at Pennington Biomedical Research Center in Baton Rouge, La., is a leader in the field of "infectobesity" (obesity of infectious origin) and has published many studies on AD36.
"This is a nice milestone for the investigation of AD36 and its role in obesity," he tells WebMD. "We have been studying this in various animal models and have found that when infected, animals gain weight."
"This association has also been seen in adults, and now for the first time, we see that it may be happening in children as well," he says.
If further research solidifies the link between this virus and obesity, it may be possible to develop a vaccine to prevent obesity -- and that would be the Holy Grail, he says. "That is why this line of investigation is really important."
Study Raises Intriguing Questions
"There was an association between having been exposed to the virus and being overweight now," says Scott Kahan, MD, co-director of the George Washington University Weight Management Program in Washington, D.C.
"This study is just a snapshot in time, so we can’t say whether having this virus causes people to gain weight or predisposes them to certain behaviors," he tells WebMD. "The study raises a lot of questions that are very reasonable to put time and effort into trying to answer."