Obesity could be caused by childhood viral infections and may not be a result of heredity or poor eating habits, according to a study done at the University of California.
They found that children exposed to a particular strain of adenovirus were significantly more likely to be obese.
Dr. Jeffrey B. Schwimmer, associate professor of clinical pediatrics at UC San Diego, and colleagues examined 124 children, ages 8 to 18, for the presence of antibodies specific to adenovirus 36 (AD36), one of more than 50 strains of adenovirus known to infect humans and cause a variety of respiratory, gastrointestinal and other infections.
AD36 is the only human adenovirus currently linked to human obesity.
A little more than half of the children in the study (67) were considered obese, based on a Body Mass Index or BMI in the 95th percentile or greater. The researchers detected neutralizing antibodies specific to AD36 in 19 of the children (15 percent).
The majority of these AD36-positive children (78 percent) were obese, with AD36 antibodies much more frequent in obese children (15 of 67) than in non-obese children (4 of 57).
Children who were AD36-positive weighed almost 50 pounds more, on average, than children who were AD36-negative.
Within the group of obese children, those with evidence of AD36 infection weighed an average of 35 pounds more than obese children who were AD36-negative.
"This amount of extra weight is a major concern at any age, but is especially so for a child. Obesity can be a marker for future health problems like heart disease, liver disease and diabetes. An extra 35 to 50 pounds is more than enough to greatly increase those risks," said Schwimmer.
Schwimmer said he hopes this research will help shift some of the burden that falls so heavily upon obese people, in particular children.
"Many people believe that obesity is one's own fault or the fault of one's parents or family. This work helps point out that body weight is more complicated than it's made out to be. And it is time that we move away from assigning blame in favor of developing a level of understanding that will better support efforts at both prevention and treatment. These data add credence to the concept that an infection can be a cause or contributor to obesity," he said.
The study is published in the latest online edition of the journal Pediatrics.