Allergy Info

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• A food allergy is “an adverse health effect resulting from a specific immune response that occurs reproducibly on exposure to a given food.”

• In plain language, a food allergy is when a person’s immune system overreacts to something in a certain food. This part of the food that the body reacts is usually a protein and is called an allergen. The immune system thinks the allergen is a threat and tries to attack it. This response can cause a range of symptoms, which are called an allergic reaction.

The prevalence of peanut allergy is variable worldwide. 

The highest rates are seen in westernized countries such as the United States, the United Kingdom, Canada, and Australia, where the prevalence is approximately 1 to 2 percent. 

However, rates are lower in other westernized countries such as France (0.3 to 0.7 percent), Denmark (0.2 to 0.6 percent),  and Israel (0.04 to 0.17 percent). 

Peanut allergy is rare in Asia, where peanut is often not found on the list of most common allergenic foods. Regional dietary habits and pollen exposure may influence the epidemiology of allergy to legumes, such as peanut.

The new research findings come from the LEAP-Trio study, which builds on the seminal results of the Learning Early About Peanut Allergy (LEAP) clinical trial and the subsequent LEAP-On study, both sponsored and co-funded by NIAID.

During the LEAP trial, half of the participants regularly consumed peanut products from infancy until age 5 years, while the other half avoided peanut during that period. 

Researchers found that early introduction of peanut products reduced the risk of peanut allergy at age 5 by 81%. Subsequently, children from LEAP who participated in LEAP-On were asked to avoid eating peanut products from ages 5 to 6 years. Investigators found that most children from the original peanut-consumption group remained protected from peanut allergy at age 6.

To Which Foods Are People Allergic?

• More than 170 foods have been reported to cause food allergy reactions in the U.S.

• In 2004, eight major food allergens—milk, egg, peanut, tree nuts, wheat, soy, fish and crustacean shellfish—were identified as responsible for at least 90 percent of the serious food allergy reactions in the U.S.

• In 2021, the U.S. added sesame as the ninth major food allergen.

• The most common food allergies in children are allergies to peanut, milk, shellfish, and tree nut.

• The most common food allergies in adults are allergies to shellfish, milk, peanut, and tree nut.

Feeding children peanut products regularly from infancy to age 5 years reduced the rate of peanut allergy in adolescence by 71%, even when the children ate or avoided peanut products as desired for many years. These new findings, from a study sponsored and co-funded by the National Institutes of Health’s National Institute of Allergy and Infectious Diseases (NIAID), provide conclusive evidence that achieving long-term prevention of peanut allergy is possible through early allergen consumption. The results were published today in the journal NEJM Evidence.

“Today’s findings should reinforce parents’ and caregivers’ confidence that feeding their young children peanut products beginning in infancy according to established guidelines can provide lasting protection from peanut allergy,” said NIAID Director Jeanne Marrazzo, M.D., M.P.H. “If widely implemented, this safe, simple strategy could prevent tens of thousands of cases of peanut allergy among the 3.6 million children born in the United States each year.”