By Salynn Boyles
WebMD Health News Reviewed by Louise Chang, MD

Aug. 14, 2008 -- Are kids with frequent ear infections at increased risk of becoming overweight later in life?

Early research suggests they are, and that damage to the nerves controlling taste may be to blame.

The research was presented for the first time today at the 116th annual convention of the American Psychological Association in Boston.

Taste researcher Linda M. Bartoshuk, PhD, of the University of Florida College of Dentistry, tells WebMD that over time, frequent ear infections may alter taste perception in a way that leads to a heightened preference for high-fat and highly sweetened foods, which, in turn, leads to obesity.

"Ear infections are relevant to taste because one of the most important taste nerves goes through the middle ear on the way to the brain," she says.

Another taste nerve is in the throat, Bartoshuk says, and researchers also presented findings showing an increased risk for obesity in children who have had tonsillectomies.

Ear Infections and Obesity

Bartoshuk says she first suspected a connection between ear infections and obesity about six years ago after analyzing findings from a survey she conducted to explore taste and health.

About 6,600 adults -- mostly academic professionals -- completed the survey, which included questions about past ear infections and current body mass index (BMI), a measure of obesity.

People with a history of frequent ear infections were found to be 62% more likely to be obese than people who reported no history of ear infection.

"We didn't expect to find ear infections associated with BMI, but that is what we saw," she says.

Bartoshuk then began looking for other research databases that included information on ear infection history and weight.

Several of these studies were presented at today's symposium, along with Bartoshuk's original research.

In one study involving middle-aged women tested for taste sensitivity, those who showed evidence of damage to taste nerves were more likely than women without evidence of nerve damage to prefer high-fat and highly sweetened foods. They were also more likely to have larger waists.

In another study, preschoolers with a history of frequent ear infections were found to eat fewer vegetables and more sweets than children who did not have frequent ear infections. They also tended to be heavier.

Epidemiologist Kathleen Daly, PhD, of the University of Minnesota-Twin Cities, reported on her work with children up to age 2, suggesting that chronic ear infections prior to this age are associated with higher BMIs (body mass index) around the second birthday.

"All of this is intriguing, but we don't really know what it means yet," Daly says.

Finally, re-examination of data from a large, national health survey conducted in the 1960s found a 30% increase in obesity risk among children who had tonsillectomies.