COLUMBUS, Ohio—An estimated 1.2% to 1.4% of Americans are allergic to peanuts, tree nuts or both; however, adults and children with allergies often struggle to accurately identify peanuts and tree nuts that are among the most common food allergens in the United States, according to a new study published in the journal Annals of Allergy, Asthma & Immunology.
Researchers at Ohio State University recruited 1,105 people (649 adults and 456 children) to investigate their nut knowledge. 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 in a patient-care setting. Participants then were asked to visually identify each of 19 nuts in a display box by writing the name of the food in a corresponding area on an answer sheet.
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 study included samples of peanuts as well as cashews, Brazil nuts, pistachios, almonds, pecans, walnuts, hazelnuts, Macadamia nuts and pine nuts.
On average, the participants correctly identified 8.4, or 44.2%, of the nuts. Adults did better than children, averaging 11.1 correct answers compared to 4.6 correct, respectively. Those age 51 or older got the most right, with an average correct 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% of participants correctly identified peanuts in a shell, compared to 80.5% who could identify a peanut outside the shell. Among tree nuts, cashews without a shell were the most commonly recognized, and hazelnuts in the shell were the least identifiable.
Only 1.9% of the study population, correctly identified all 19 forms of nuts; 2.4% of participants reported that they had 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 who had backgrounds in child care, food preparation or a medical field did not do significantly better than others at identifying the nuts.
The findings suggest that education about the appearance of all forms of peanuts and tree nuts is an important follow-up to the diagnosis of any kind of nut allergy, researchers say.
"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.