Stem cell cold virus = Obesity?

In the buffet of reasons for why obesity is becoming an epidemic, researchers are piling more evidence on the plate for one still-controversial cause: a virus.

In the buffet of reasons for why obesity is becoming an epidemic, researchers are piling more evidence on the plate for one still-controversial cause: a virus.

New research has found that when human stem cells, the blank slate of the cell world, are exposed to a common virus they turned into fat cells. They didn8217;t just change, they stored fat, too.

While this may be a guilt-free explanation for putting on pounds, it doesn8217;t explain the growing obesity problem fully. But it adds to other recent evidence that blames expanding waistlines on more than just super-sized appetites and underused muscles.

For several years, researchers have looked at a possible link between obesity and this common virus, called adenovirus-36, from a family of viruses that cause colds and pinkeye in people. They had already found that a higher percentage of fat people had been infected with the virus than nonfat people. They had exposed animals to the virus and got them to fatten up and even found a gene in the virus that causes animals to get obese.

But ethical restraints kept researchers from exposing people to the virus. So they did what would be considered the next best thing, said Nikhil Dhurandhar, who headed the research at the Pennington Biomedical Research Center in Louisiana State University. They took fat tissue from people who had liposuction, removed adult stem cells and exposed the cells to the virus in the lab. Adult stem cells can regenerate and turn into different types of specialised cells to help the body heal itself.

More than half the stem cells exposed to the virus turned into fat cells and accumulated fats, said researcher Dr Magdalena Pasarica, who presented the results at the American Chemical Society8217;s meeting in Boston.

8220;It8217;s the first time we see an effect in human cells,8221; Pasarica said. If a viral cause of obesity can be confirmed, a vaccine could be developed, maybe within five to 10 years, to prevent the virus from making some people fat, Dhurandhar said. However, it wouldn8217;t help people already obese, he said.

Story continues below this ad

Outside experts are intrigued but worry about people blaming all obesity on viruses, when this may be just one of many causes. 8220;The cause for obesity in everyone is the same,8221; said Dr Samuel Klein, director of the Center for Human Nutrition at the Washington University School of Medicine in St Louis. 8220;You eat more calories than you burn up; You can8217;t get away from that basic law of physics.8221;