Adenovirus Type 2 Infection

That Pesky Obesity Virus

That pesky obesity virus keeps cropping up in the scientific literature. A new meta-analysis of 2,508 subjects with obesity and 3,005 controls in Obesity finds that infection with adenovirus 36 (Ad36) brings an increased risk of obesity.

We now have about 100 scientific publications on Ad36 and obesity. Animal studies have shown that Ad36 causes obesity in chickens, mice, rats, and monkeys. The link between Ad36 and obesity in humans has been pretty well documented, but causality is a challenge to prove. Don’t expect any prospective, controlled studies to see what happens when we infect humans. A solid longitudinal study might help persuade the skeptics, but that remains to be seen.

Earlier this year, when Nikhil Dhurandhar and a team of scientists from five institutions published an analysis of changes in adiposity and glycemic control associated with Ad36 infection, skeptics were unmoved. In a commentary, Tomohide Yamada et al said:

In our opinion, Ad36 infection might be associated with obesity, but it seems too early to discuss the clinical implications or the development of new approaches for prevention and treatment.

Too early to discuss? It’s hard not to think that some experts are so invested in the paradigm of obesity as a voluntary disease of diet and exercise that a viral etiology is too much to even consider, much less discuss.

Asked about this state of affairs, Richard Atkinson, an accomplished scientist in Ad36 research, said, “We may have to wait for a new generation of scientists who can accept that some obesity might be caused by a virus.”

Sadly, he may be right.

Click here to read the new meta-analysis of ad36 infection and obesity, click here to read Dhurandhar’s study of Ad36, adiposity, and glycemic control, and click here to read the skeptical commentary.

Human Bronchial Epithelial Cells Infected with Adenovirus Type 2, photograph © Zeiss Microscopy / flickr

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