14 DAY TRIAL // We hear all the time that many diseases are linked to obesity. But now, a team led by a researcher of the Pennington Biomedical Research Center at Louisiana State University in Baton Rouge Louisiana State University, Dr. Magdalena Pasarica, born in Romania, has found that obesity itself is a disease. More precisely, an infection, provoked by a virus linked to conjunctivitis and respiratory affections.
Previously, the only known factors to induce obesity were over-eating, high-fat diet, lack of exercise, a genetic factor and certain medications. And the about 97 million American adults who are overweight or obese are more vulnerable to Type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis and other diseases.
Lab experiments revealed that infection with human adenovirus-36 (Ad-36), long known for causing respiratory and eye infections in humans, turns adult stem cells taken from fat tissue into fat cells. Those stem cells not in contact with the virus went unchanged.
The research team also detected a viral gene appearing to be linked to the obesity effect. This means that a future vaccine or antiviral medication could treat viral obesity.
"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. Not all infected people will develop obesity. 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." said Pasarica.
A team at the same center showed that Ad-36 can make the infected animals store fat. The same team revealed that 30 % of obese people were infected with the Ad-36 virus, while only 11 % of lean persons .
"But evidence that the virus could actually cause fat levels to increase in human cells was lacking until now," said Pasarica.
The research team experimented on adult stem cells from fatty tissue from a wide range of patients who had undergone liposuction. 50 % of the stem cells were exposed to Ad-36, the others were not. In about a week, most of the virus-infected adult stem cells turned into fat cells, a fact not observed in the other stem cells. A recently discovered Ad-36 gene could be linked to fat storing found in infected animals.
"That gene, called E4Orfl, is now emerging as a promising target for future human therapies, such as vaccines and anti-viral medicines, aimed at preventing or inhibiting the obesity virus. The exact mechanism by which the virus might cause obesity in people is currently unknown," said Pasarica, who pointed out that other human viruses could also induce obesity. Other 9 pathogens are suspected and there may be more.
Studies are required to assess how long the virus stays in the body of obese individuals and how long the fat-enhancing effect lasts once the virus is eliminated.
"A recent study demonstrated that animals that developed the virus remained obese up to six months after their infection was gone. More studies are needed, especially in humans," added Pasarica.