Obesity and the common cold | Science News for Students

Obesity and the common cold

A study of children finds those who caught a particular virus were more likely to be obese
Oct 5, 2010 — 7:20 pm EST

When you cough and sneeze, someone may tell you that you caught a cold. But often, what you really “caught” was a virus — a tiny organism that can spread infection. The drippy, stuffy, and uncomfortable symptoms of the common cold show up when a person is infected with a kind of virus.

In recent studies, scientists report that one kind of virus that causes the common cold may be connected to another dangerous health problem: Obesity. A person is obese if he or she has a lot of fat and is extremely overweight. Obesity has been linked to serious health risks such as heart disease. In other words, obesity can cause big problems.

For both children and adults, obesity is dangerous. Researchers say that obesity among children is an epidemic. An epidemic happens when many people get sick with a disease at the same time. Childhood obesity is called an epidemic because so many children are now extremely overweight.

Studies have shown that obese children are more likely to become obese adults, who are at higher risk for such major health problems as diabetes, heart disease and some kinds of cancer.

An illustration of adenovirus-36Poor nutrition and a lack of exercise can lead to obesity. But another, less obvious culprit could be a virus called adenovirus-36, which causes a cold. Within one group of children recently studied, those who had caught adenovirus-36 were more likely to be obese.

Jeffrey Schwimmer led the study. He is a pediatric gastroenterologist at the University of California, San Diego and at Rady Children’s Hospital San Diego. A pediatrician is a doctor who treats infants and children, and a gastroenterologist is a doctor who studies diseases in the parts of the body that food passes through, including the stomach and intestines.

Schwimmer and his team took blood samples from 67 obese children and 57 normal-weight children. The youngest children were eight and the oldest were 18. Schwimmer was looking for antibodies.

Antibodies are the human body’s way of fighting disease. When an infection begins in the body, the immune system fights back by creating antibodies that destroy the invaders. After the infection is gone, the antibodies remain in a person’s blood. This fact makes antibodies useful to researchers like Schwimmer. If he finds the adenovirus-36 antibodies in a blood sample, he knows the person was infected with the virus in the past.

The study showed that 19 of the children had the antibodies. Fifteen of those children were obese, and four were normal-weight. He also found that obese children with the antibodies were 35 pounds heavier, on average, than obese children without the antibodies.

This study is not the first time scientists have connected the virus to obesity. Other experiments have shown that many animals gain weight after infection by the virus, even though their eating and exercise habits don’t change. Laboratory experiments suggest that the virus can make the human body produce more fat cells.

Schwimmer says he’s found a connection, but it’s too early to know for certain if the adenovirus-36 virus actually causes obesity. “I don’t think we know enough to say, ‘Oh, if you get this virus you’re going to be obese,” he told Science News.

Power Words

(from the American Museum of Natural History, Yahoo! Kids Dictionary and MedlinePlus Medical Encyclopedia)

obese for children, having a BMI equal to or greater than the 95th percentile, according to the Centers for Disease Control and Prevention. BMI, or body mass index, compares a person’s weight and height in order to determine amount of body fat.

antibodies any of a large number of proteins that are produced, as part of the body’s immune response, in response to an antigen which it then neutralizes, tags or destroys.

antigen something from outside the body, such as a bacteria or virus or pollen, that enters the body and triggers a response by the immune system.

gastroenterology the branch of medicine dealing with the study of disorders affecting the stomach, intestines and associated organs.

virus ultramicroscopic infectious agent that replicates itself only within cells of living hosts.

epidemic a widespread outbreak of an infectious disease where many people are infected at the same time.