A new study indicates there may be yet another reason to reduce
childhood obesity — it may help prevent allergies. The study
published in the May issue of the Journal of Allergy and Clinical
Immunology showed that obese children and adolescents are at increased
risk of having some kind of allergy, especially to a food. The
study was funded by the National Institute of Environmental Health
Sciences (NIEHS) and the National Institute of Allergy and Infectious
Diseases (NIAID), both parts of the National Institutes of Health.
"We found a positive association between obesity and allergies," said Darryl
Zeldin, M.D., acting clinical director at NIEHS and senior author on the paper.
The researchers analyzed data on children and young adults ages 2 to19 from a
new national dataset designed to obtain information about allergies and asthma. "While
the results from this study are interesting, they do not prove that obesity causes
allergies. More research is needed to further investigate this potential link," Zeldin
The study is the first to be published using new data from the National Health
and Nutrition Examination Survey (NHANES). NHANES is a large nationally representative
survey conducted by the National Center for Health Statistics, a part of the
Centers for Disease Control and Prevention. NHANES is designed to assess the
health and nutritional status of adults and children in the United States. An
allergy/asthma component was supported by NIEHS and added to the 2005–2006 NHANES
study, making it the largest nationally representative dataset of allergy and
asthma information ever assembled in the United States.
"We have all the pieces of the puzzle in this dataset," said Zeldin. "The allergy
and asthma component of NHANES provides allergen exposure information, allergic
sensitization information, as well as disease outcome information. There is a
wealth of knowledge we will be able to gain by analyzing these data that will
be useful to allergy and asthma sufferers."
In this study, the researchers analyzed data from 4,111 children and young adults
aged 2-19 years of age. They looked at total and allergen-specific immunoglobulin
E (IgE) or antibody levels to a large panel of indoor, outdoor and food allergens,
body weight, and responses to a questionnaire about diagnoses of hay fever, eczema,
and allergies. Obesity was defined as being in the 95th percentile of the body
mass index for the child’s age. The researchers found the IgE levels were higher
among children who were obese or overweight. Obese children were about 26 percent
more likely to have allergies than children of normal weight.
"The signal for allergies seemed to be coming mostly from food allergies. The
rate of having a food allergy was 59 percent higher for obese children," said
NIEHS researcher Stephanie London, M.D., a co-author on the study.
"As childhood obesity rates rise, NIEHS will continue to work to determine how
environmental factors affect this epidemic," said Linda Birnbaum, Ph.D., NIEHS
director. "Seeing a possible link between obesity and allergies provides additional
motivation for undertaking the challenge of reducing childhood obesity."
"Given that the prevalence of both obesity and allergic disease has increased
among children over the last several decades, it is important to understand and,
if possible, prevent these epidemics," said Cynthia M. Visness, Ph.D., lead
author on the paper and a scientist at Rho Federal Systems Division, Inc. in
Chapel Hill, N.C.
NIAID conducts and supports research — at NIH, throughout the United States,
and worldwide — to study the causes of infectious and immune-mediated diseases,
and to develop better means of preventing, diagnosing and treating these illnesses.
News releases, fact sheets and other NIAID-related materials are available on
the NIAID Web site at http://www.niaid.nih.gov.
The NIEHS supports research to understand the effects of the environment on human
health and is part of NIH. For more information on environmental health topics,
visit our website at http://www.niehs.nih.gov.
The National Institutes of Health (NIH) — The Nation's
Medical Research Agency — includes 27 Institutes and
Centers and is a component of the U.S. Department of Health and
Human Services. It is the primary federal agency for conducting
and supporting basic, clinical and translational medical research,
and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and
its programs, visit www.nih.gov.