Having a nut allergy may not necessarily mean your nut-eating days are over, according to a study published in Annals of Allergy, Asthma & Immunology. Researchers have found that people with a clinically diagnosed tree nut allergy may be able to eat certain nuts without having an allergic reaction. Tree nuts include almonds, cashews, walnuts, hazelnuts, pecans, pistachios, Brazil nuts, and others. The study looked at data from 109 people who tested positive for a tree nut allergy via a skin prick test (SPT) and/or a blood test. The participants were classified as belonging to one of three groups: a tree nut allergy group, who experienced clinical symptoms after eating tree nuts and had tested positive on one or both allergy tests; a tree nut sensitization group, who tested positive on one or both allergy tests and had never eaten nuts as a result; and a tree nut avoidant group, who never ate nuts because of a perceived possibility of a tree nut allergy, even though they hadn't been tested previously. The participants were then given oral food challenges (OFCs), where they ate tree nuts to which they had tested positive on one or both allergy tests. Importantly, nuts that had caused allergic symptoms in the past weren't used in OFCs. The researchers found that:
86% of all participants had no allergic symptoms, such as hives, swelling, and wheezing, after OFCs.
76% of OFCs in the tree nut allergy group, 91% of OFCs in the tree nut sensitization group, and 100% of OFCs in the tree nut avoidant group caused no allergy symptoms.
Almonds were the least allergenic nuts, causing no allergic symptoms in any of the participants who underwent almond OFCs.
The results suggest that some tree nuts may be safe to eat, even in those who have tested positive on skin prick or blood tests, and in those who have experienced allergic symptoms to other tree nuts. These findings are important as increasing numbers of people report tree nut allergies—this number has tripled in the last ten years. But the results don’t mean people with nut allergies should go nutty with other nuts. If you have a tree nut allergy or have had positive tree nut allergy tests, talk with your doctor to determine which nuts, if any, are safe for you to eat.
Source: Annals of Allergy, Asthma & Immunology