Screen Readers Skip to Content
🖶 Print page

Peanut or Tree Nut Allergy Study

Published: 2012-03-15 - Updated: 2022-10-17
Author: Ohio State University | Contact:
Peer-Reviewed Publication: Yes
Additional References: Food Allergies Publications

Synopsis: Adults and children in a recent study could correctly identify, on average, fewer than half of an assortment of the peanuts and tree nuts that are among the most common food allergens in the United States. Overall, this study found that adults and children are unreliable at visually identifying most nuts. Although adults performed better than children, they still answered only an average of 58 percent correct. Though many people might experience disagreeable symptoms when they eat peanuts or tree nuts, those diagnosed with the allergy are susceptible to life-threatening anaphylaxis if they ingest these foods.



Tree Nuts

What is the difference between tree nuts and other nuts? Although peanuts and tree nuts are classified as nuts, they are listed as separate categories in the allergen listing because they are grown on different plants. Tree nuts grow on trees, whereas peanuts grow underground and are considered legumes. Tree nuts include almonds, Brazil nuts, cashews, hazelnuts, pecans, pistachios, and walnuts. A drupe is a fruit in which an outer fleshy part surrounds a shell (what we sometimes call a pit) with a seed inside. Some examples of drupes are peaches, plums, and cherries - but walnuts, almonds, and pecans are also drupes.

Main Digest

Parents of children with peanut and tree-nut allergies did no better at identifying the samples in the survey than did parents of children without this food allergy. And only half of the participants with a peanut or tree-nut allergy correctly identified all forms of the nuts to which they were allergic.

Related Publications:

A nut allergy is an allergic reaction when someone's immune system mistakenly believes something harmless, such as a tree nut or peanut, is harmful. The immune system responds by creating specific antibodies to proteins in that food. These antibodies - called immunoglobulin E (IgE) - are designed to fight off the "invading" proteins.

Allergic reactions to nuts can progress rapidly to anaphylaxis. Peanut allergy is responsible for more deaths than any other type of allergy. Tree nuts are sometimes used in lotions and shampoos. Be sure to check these products' labels and food labels.

Photo of assorted types of nuts in various containers.
Photo of assorted types of nuts in various containers.

The Study

The 19 samples included various nuts in and out of the shell, and some were chopped, sliced, or diced just as they appear on grocery store shelves.

The findings suggest that education about the appearance of all forms of peanuts and tree nuts is an important follow-up to diagnosing any nut allergy, researchers say. An estimated 1.2 to 1.4 percent of Americans are allergic to peanuts or tree nuts.

"When we ask patients to avoid peanuts and tree nuts, we shouldn't assume patients know what they're looking for because they may not. It's worthwhile to do some education about what a tree nut is, what a peanut is, and what they all look like," said Todd Hostetler, assistant professor of pediatrics and internal medicine at Ohio State University and lead author of the study.

The study included peanuts, cashews, Brazil nuts, pistachios, almonds, pecans, walnuts, hazelnuts, Macadamia nuts, and pine nuts. The research is published in a recent issue of the journal Annals of Allergy, Asthma & Immunology.

Nuts are the leading cause of death from food-induced allergic reactions, so avoiding eating them is the primary way to manage this allergy. Though many people might experience disagreeable symptoms when they eat peanuts or tree nuts, those diagnosed with the allergy are susceptible to life-threatening anaphylaxis if they ingest these foods. Anaphylaxis most commonly involves itchy hives on the skin. Still, it can rapidly progress to include coughing, wheezing, shortness of breath, swelling of the airway, cardiovascular problems, and abnormally low blood pressure.

People who are diagnosed with an allergy to one kind of nut are generally advised to avoid eating all nuts because of their similar appearance and the likelihood that they will be mixed, said Hostetler, an allergist/immunologist who treats patients at Nationwide Children's Hospital and Wexner Medical Center at Ohio State.

A total of 1,105 people - 649 adults and 456 children - participated in the study, which was set up for eight days outside a popular exhibit at the Columbus science museum COSI in the spring of 2010. Participants completed questionnaires about their demographic information and any personal history of an allergy to peanuts or tree nuts.

Those age 15 or older were asked to complete family histories of this food allergy and document any current or previous jobs in child care or teaching, food preparation or serving, or a patient-care setting. Participants were then asked to visually identify each of the 19 nuts in a display box by writing the name of the food in a corresponding area on an answer sheet. The participants correctly identified 8.4, or 44.2 percent, of the nuts.

Adults did better than children, averaging 11.1 correct answers compared to 4.6 correct, respectively. And the older the participant, the better the outcome: Those age 51 or older got the most right, with a correct average number of 13 out of the 19 nuts displayed.

Peanuts were the most commonly identified item, and the shell made a significant difference: Almost 95 percent of participants correctly identified peanuts in a shell, compared to 80.5 percent who could identify a peanut outside the shell. The most commonly recognized cashews without a shell and hazelnuts in the shell were the least identifiable among tree nuts.

Only 21 participants, or 1.9 percent of the study population, correctly identified all 19 forms of nuts.

Twenty-seven, or 2.4 percent, participants reported having a peanut or tree-nut allergy. There was no statistical difference between their average number of correct answers vs. correct answers by those who did not have allergies. Though being a parent was associated with better overall performance on the survey, parents of allergic children did not perform any better than did parents of nonallergic kids.

Participants with backgrounds in child care, food preparation, or the medical field did not do significantly better than others at identifying the nuts.

"Overall, this study found that both adults and children are not reliable at visually identifying most nuts. Although adults performed better than children, they still answered only an average of 58 percent correct," Hostetler said.

"On the one hand, you'd like to think adults would be better at this, but I looked at myself before the study and realized I didn't know all of them, either. Perhaps the more familiar people are with what peanuts and tree nuts look like, the better they'll be at successfully avoiding them when needed."

Co-authors of the study included Sarah Hostetler and Bryan Martin of the College of Medicine and Gary Phillips of the Center for Biostatistics, all at Ohio State.

Reference Source(s):

Peanut or Tree Nut Allergy Study | Ohio State University ( Disabled World makes no warranties or representations in connection therewith. Content may have been edited for style, clarity or length.

Post to Twitter Add to Facebook

Disabled World is an independent disability community established in 2004 to provide disability news and information to people with disabilities, seniors, their family and/or carers. See our homepage for informative news, reviews, sports, stories and how-tos. You can also connect with us on Twitter and Facebook or learn more about Disabled World on our about us page.

Disabled World provides general information only. The materials presented are never meant to substitute for professional medical care by a qualified practitioner, nor should they be construed as such. Financial support is derived from advertisements or referral programs, where indicated. Any 3rd party offering or advertising does not constitute an endorsement.

Cite This Page (APA): Ohio State University. (2012, March 15). Peanut or Tree Nut Allergy Study. Disabled World. Retrieved January 27, 2023 from

Permalink: <a href="">Peanut or Tree Nut Allergy Study</a>