Web edition: December 17, 2010
Print edition: January 1, 2011; Vol.179 #1 (p. 35)
Thank you for great reporting. I’m a longtime subscriber to Science News (since the 1970s) and want to compliment your reporters, writers and editors on the high quality of your articles, which often involve material that is difficult to explain. They make the news of science understandable, informative and entertaining. Hopefully, publications like yours, together with good science education in our schools, will inspire our youth and combat the politicized science and the pseudoscience now prevalent in our society.
Leon R. Pacifici, Underhill, Vt.
Viral infection and obesity
The correlation between obesity and adenovirus-36 antibodies (SN: 10/9/10, p. 5) is interesting, but what is causing what? The article says 22 percent of obese children and 7 percent of normal-weight children in the study carried the antibodies. For a virus as “common” as the common cold, these seem like low exposure rates. Is it possible that many people are exposed but either never develop or stop producing the antibodies? Or that obese people produce more of the antibodies than nonobese people?
Tom Lippe, El Cerrito, Calif.
It’s true that cause and effect can’t be established by association studies, such as the one by Jeffrey Schwimmer and colleagues showing a link between adenovirus-36 infection and childhood obesity. But this study is just one of many, including research showing that more body fat accumulates in animals infected with AD-36. Researchers now plan to follow groups of people to see whether body-fat patterns change after infection with the virus. As for exposure rates, the common cold is caused by many different types of viruses, not just adenoviruses, so the rates in the study aren’t necessarily low. Adenoviruses account for only about 8 percent of viral illnesses, including respiratory and gastrointestinal illnesses, Schwimmer says. In people with normal immune systems, viral infections lead to antibody production, although it may take a few days or weeks. If anything, obese children might make fewer antibodies than nonobese children do, since obesity is linked to suppression of the immune system. — Tina Hesman Saey