Food Allergy Research

New Insights on How Children Develop Allergies and Why Some Outgrow Them

Many children outgrow their food allergies as they reach their teenage or adult years. A food that used to cause a reaction by the immune system in a negative way is now neutral; the food is tolerated.

A new study published in the January 28, 2016, online issue of Science by La Jolla Institute for Allergy and Immunology (LJI) may explain how children might develop tolerance to foods over time. It also provides important clues as to why they are more prone to food allergies than adults in the first place.

When a new food enters the body for the first time, the immune system should identify the food protein as a “friend”. Identifying the food as a “friend” releases a certain type of immunosuppressive cell called “Treg” cells, which allow the body to use the food as nutrient and safely consume it. This study showed that eating a “normal diet,” one with a variety of unique foods, stimulates the production of Treg cells.

Using germ-free mice raised and bred on an elemental diet, researchers were able to represent an “immunological blank state” to test whether these special mice would produce Tregs. Researchers found that these mice were depleted of Tregs in the small intestine whereas a large number were found in mice fed a “normal” diet. The “normal” food proteins in the diet and the beneficial bacteria in the intestine generated a defensive army of Tregs, primed to stop an inflammatory response to food.

Study results suggest that the consumption of different types of foods in the diet stimulates cells in the gut that suppress rejection of food by the immune system.

A press release from LJI states, “Knowing this could explain why children, who have more limited exposure to novel foods than adults, are more susceptible to food allergies. It also suggests what happens on a cellular basis as some outgrow it: namely, they may be expanding their repertoire of Tregs that recognize new foods as ‘safe’.”

Please note that these mouse-model results need to be verified in humans before conclusions can be drawn.

For an in-depth look at this study, read a press release from LJI.

4 thoughts on “New Insights on How Children Develop Allergies and Why Some Outgrow Them

  1. I’m always interested in learning more about food allergies, as my son had a “full bucket” of them when he was 10 months old. But it can be a bittersweet effort. The latest, that children don’t have an exposure to a variety of foods and so the first peanut, the first egg, the first sip of cow’s milk in Enfamil, when Tregs aren’t formed, can result in allergies, seems facile at best. In the current environment, where parents are more careful with foods, I suspect that you’re observing people who don’t vary the child’s diet from fears brought on by a greater incidence of allergies. And yet the child still has allergies. We did it all and our kid was diagnosed with 17 allergies to milk, eggs, tree nuts, soy, sesame, grains like wheat and oats, meat and fish. So much for a varied and measured exposure to potential allergens.

  2. My son is allergic to fish, we realized after a few serious allergic reactions after he ate it and then his throat was closing and couldn’t breathe just after brushing his hand against a bag of frozen fish in the freezer. He has been hoping to go fishing with his father his whole life, and he recently got retested (bloodwork) and his reaction levels were low. His levels were higher to peanuts and he eats Reese’s peanut butter cups with no problems. My husband was thrilled with the results thinking that he has grown out of his fish allergy but I am still too nervous. Can these results b wrong? The dr. Says the only way to know for sure is to have him try it and see what happens😦Any thoughts?

    1. Danielle – we just did a webinar this week on oral food challenges, which are done in a doctor’s office. There is understandably some anxiety that comes with these challenges, but they can improve quality of life either way from the outcome (either you know he’s still allergic, or you can reintroduce the food and the fishing!) Look for the recording of that webinar to be posted here:, and this post is also a good resource:

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