The high incidence of food allergy in children, and the reason many kids eventually outgrow their allergy, may have to do with our immune system’s natural learning curve.
When we consume a new food the nutrients in it are foreign to our body, and the immune system functions to protect us from substances that are foreign. Fortunately, our bodies also produce a population of specific T cells that allow us to acquire a tolerance for foreign, or unfamiliar foods.
This immune system learning process may look something like this:
- New food molecules are ingested containing markers called antigens. Antigens signal our immune system that an unfamiliar visitor, such as a protein, has arrived.
- The presence of unfamiliar nutrients triggers the development of immunosuppressive T-regulatory cells, called “Treg” cells, in our gut.
- Treg cells may sound like the name of alien invaders in a sci-fi movie, but in our body Tregs are digestive allies. They keep our immune system from attacking an unfamiliar nutrient, allowing the nutrient to nourish our body.
Scientists also believe that healthy intestinal bacteria help to stimulate the production of Tregs, and research suggests the presence of both microbe and food induced Treg populations are needed to avert allergic reactions.
Kid and Tregs
Because children naturally have a more limited exposure than adults to a variety of novel foods, their Treg populations are less evolved, leaving kids more susceptible to food allergies. As children mature and their Treg communities flourish, their immune system may become tolerant of a food once treated as unsafe—and they outgrow their allergy.
However, this understanding of Treg development does not imply that we should start feeding our children differently. What scientists know about Tregs has been gleaned from research involving some stalwart laboratory mice, and only serves to further our understanding of how food tolerance develops over time. Practical applications may follow future studies involving humans.