Millions of Americans have a food allergy

A study funded by the National Institute of Health (NIH) in the USA has developed estimates of the prevalence of and demographic risk factors for food allergy, and investigated associations of food allergy with asthma, hay fever, and eczema. These nationally representative estimates suggest 2.5 percent of Americans (7.5 million people) have at least one food allergy and young black children with asthma appear to be at the highest risk.

The study is thought to be the largest investigation to-date into food allergy, including blood samples from more than 8,200 participants with food-specific serum IgE measured to peanut, cow's milk, egg white, and shrimp. Researchers also used self-reported data to evaluate demographic risk factors and associations with asthma and related conditions.

Results of the study indicate children younger than 5 were more than twice as likely as those older than 20 to have a food allergy. Black people were three times as likely as white people to have allergy to at least one food. More men than women were found to have food allergy, with black boys under 5 years more than four times as likely as white women over 20 to have a food allergy.

Those with asthma had nearly four times the risk of having a food allergy than those without it. People who had received emergency care for asthma in the 12 months prior to the survey were nearly seven times more likely to have food allergies than non-asthma sufferers.

While previous research has reported higher numbers of national food allergy prevalence, authors of the current study say the latest findings cannot be accurately compared with previous findings due to the use of different methodologies, different criteria and different population sizes.

Reference:Liu et al. Journal of Allergy and Clinical Immunology. 2010. Vol 126(4):798-806.e13