Why the overlap in peanut and tree nut allergies?
My wife is severely allergic to both tree nuts and peanuts (as in full on anaphylaxis, hello epipen and ER). We both find this curious, since peanuts are legumes and not nuts at all. Informally we've heard there is about a 10% overlap in these allergies. Does anyone know why that might be? I know this seems more like a medical than cooking question, but I think it has a relevance to cooking as it helps us understand both the composition of these foods and how we may best as cooks help to avoid poisoning people we cook for.
Best Answer
So from this - http://content.karger.com/produktedb/produkte.asp?typ=pdf&file=IAA2003131004234 - it sounds like they both share IgE-reactive (http://en.wikipedia.org/wiki/Immunoglobulin_E) epitopes.
Both native and recombinant nut allergens have been identified and characterized and, for some, the IgE-reactive epitopes described. Some allergens, such as lipid transfer proteins, profilins, and members of the Bet v 1-related family, represent minor constituents in tree nuts. These allergens are frequently cross-reactive with other food and pollen homologues, and are considered panallergens. Others, such as legumins, vicilins, and 2S albumins, represent major seed storage protein constituents of the nuts.
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Why are peanuts a separate allergen from tree nuts?
The proteins in peanut are very different to those in tree nuts which include almonds, Brazil nuts, cashews, hazelnut, macadamia nuts, pecans, pistachios or walnuts. Therefore, someone who is allergic to peanut is not automatically going to be allergic to tree nuts.Is it possible to have both a peanut allergy and a tree nut allergy?
But the proteins in peanuts are similar in structure to those in tree nuts. For this reason, people who are allergic to peanuts can also be allergic to tree nuts, such as almonds, Brazil nuts, walnuts, hazelnuts, macadamia nuts, pistachios, pecans, and cashews.Why are peanuts and tree nuts different?
It's actually a legume. Peanuts are legumes, which are edible seeds enclosed in pods, and are in the same family as beans, lentils, and peas. Meanwhile, tree nuts, which include but are not limited to, walnuts, cashews, almonds, and pecans, are all produced on trees.Can you be allergic to peanuts but not other nuts?
Peanuts are legumes and don't share the same protein structure as tree nuts. It is, however, possible to have an allergy to peanuts and various types of tree nuts.Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
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