New Data Analysis Shows Possible Link between Childhood Obesity and Allergies
A new study indicates there may be yet another reason to reduce childhood obesity—it may help prevent allergies.
Balintfy: A study published in the May issue of the Journal of Allergy and Clinical Immunology shows that obese children and adolescents are at increased risk of having some kind of allergy, especially to a food. Dr. Darryl Zeldin is a senior investigator and acting clinical director at the National Institute of Environmental Health Sciences. He explains that researchers analyzed data from more than four-thousand children and young adults age 2 to19.
Zeldin: In short what we found was that being obese or overweight was associated with increased risk of allergy.
Balintfy: Dr. Zeldin adds that while the results from this study are interesting, the association does not prove that obesity causes allergies.
Zeldin: We simply can say that the two are associated. That if you're obese you're more likely to have allergies, if you're not obese, you're less likely to have allergies, but we can't say that obesity causes allergies.
Balintfy: The study is the first to be published using a new national dataset designed to obtain information about allergies and asthma.
Zeldin: The data is from a cross sectional study, and what that means is that we take a snapshot of the U.S. population at a single point of time. So because we don't know whether the timing of the exposure is before or after the health outcome, in this case allergy, we can't really determine causality.
Balintfy: The data is from the National Health and Nutrition Examination Survey, called NHANES [EN-Hanes] that is conducted every year by the Centers for Disease Control and Prevention's National Center for Health Statistics.
Zeldin: The strength of large national surveys like NHANES are that they allow one to look at associations and then set the stage for subsequent more detailed studies that can address the issue of causality. Right now in the literature, the medical literature, there is controversy as to whether there is a relationship between obesity and allergy. Some studies that have been published suggest there is a relationship, other studies that have been published suggest there isn't; they're all small studies. But what the NHANES study adds to the puzzle, if you will, is it's a large study, it's nationally representative, and it clearly shows a relationship. That relationship can now be tested to look to see whether, for example intervening to reduce overweight, might reduce the prevalence of allergy in the population.
Balintfy: Dr. Zeldin emphasizes that being obese or overweight, is associated with increased risk of food allergy.
Zeldin: And that's important because food allergy is not uncommon in children and obesity is not uncommon in children. And given that both of these problems, food allergy and obesity, appear to be increasing in the population, studying these issues and their relationship is important.
Balintfy: For more information on this study, visit www.niehs.nih.gov. This is Joe Balintfy, National Institutes of Health, Bethesda, Maryland.