Infancy vs. adulthood: When food allergies strike

In a recent interview with food allergy expert Dr. Steve Taylor, Food Safety Magazine noted that U.S. food recalls increased by about 22% in 2016 compared to 2015. A large number of recalls were due to undeclared allergens.

Allergies themselves are on the rise as well, at least in the developed world. And while most people are aware of their food allergies from a young age, sometimes we find them developing during adulthood. Taylor addressed the topic of when allergies develop during the interview.

Allergies in infants

While there is not much research on adult allergies, current science on infants has revealed new insights.

“Now, we do have a better understanding about the development of food allergies in young infants thanks to some recent observations in a huge study called LEAP, or Learning Early About Peanuts,” Taylor said.

The study found that babies aged four to six months were less likely to develop peanut allergies when exposed to peanuts in their food than babies who were restricted from peanuts. These findings go against the common advice for young parents to keep their infants away from potential allergens, like peanuts.

“This all started with an observation that peanut allergies almost don’t exist in Israel,” said Taylor. In Israel, a common snack food made with peanut butter is often given to infants, who can easily gum the snack without teeth — exposing them to small doses of peanut from an early age.

The idea is this exposure helps the babies’ immune systems learn the proper way to react to peanuts. Another recent study suggests that peanut-allergic kids treated with peanut-protein immunotherapy maintained a tolerance for their allergen thanks to the exposure.

Adult-onset food allergies

What prompts an already mature immune system to reject foods it has accepted for years? Although uncommon, adult-onset food allergies change the lives of those they affect. Favorite foods such as shrimp or nuts go out the door, and a life of scrutinizing food product labels to remain safe begins.

A 2014 study reported that of around 5% of U.S. adults with a food allergy, 15% of them were diagnosed in adulthood. In many cases, it seemed patients had lost tolerance to foods they had eaten before. The study’s authors note, however, the possibility that already-existing allergies had simply become more severe as patients grew older, or that patients were more likely to seek treatment for reactions than they had been in their youth.

The study was unable give an explicit answer as to why adult-onset food allergies occur, but was able to garner some information:

  • The most common allergies developed were to shellfish and tree nuts.
  • More women than men developed adult allergies.
  • Most patients began having reactions in their 30s.

Some people also develop mild allergies to foods related to pre-existing allergies. For example, shellfish and dust mites share some proteins, so someone with an allergy to dust mites might end up with a shellfish allergy as well.

Researchers hope this information will be useful for future studies.

Dr. Taylor is co-founder and co-director of the University of Nebraska’s Food Allergy Research and Resource Program (FARRP). Neogen’s food allergen testing products have been developed in close cooperation with FARRP (www.farrp.org).

Neogen is a leader is food safety solutions and develops test kits to detect food allergens. For more information, click here.

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