Q:

8/7/2013
If a person has a known pecan allergy, would it be harmful for that person to eat bacon that was smoked on pecan wood?

A:

Thank you for your inquiry.

Unfortunately, there is no information in the literature that would allow us to offer you a credible answer to your question. The only entries on the Internet in this regard are on discussion boards and these are not corroborated by any data.

The only thing that we do know is that there are allergens in pecans that are heat-stable (lipid transfer proteins and seed storage proteins - see abstract copied below) , but we do not know if any of these are contained in the smoke emanating from the wood or even in the wood itself. Thus, as noted, I am afraid there is no information that we can trust to answer your inquiry.

Thank you again for your inquiry and I am sorry we could not be of more help.

Allergy. 2013 Jul 29. doi: 10.1111/all.12185. [Epub ahead of print]
A systematic review of the effect of thermal processing on the allergenicity of tree nuts.
Masthoff LJ, Hoff R, Verhoeckx KC, van Os-Medendorp H, Michelsen-Huisman A, Baumert JL, Pasmans SG, Meijer Y, Knulst AC.
Source
Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht, The Netherlands.
Abstract
Background: Allergenicity of foods can be influenced by processing. Tree nuts are an important source of nutrition and increasingly consumed; however, processing methods are quite variable and data are currently lacking on the effects of processing on allergenicity.
Objective: To perform a systematic literature review on the effects of food processing on the allergenicity of tree nuts.
Methods: A systematic literature search of PubMed and Embase databases was performed, with screening of references, related articles and citations. Studies were included if they assessed the allergenicity or immunogenicity of processed nuts.
Results: The search resulted in 32 articles suitable for analysis. Clinical studies indicate that roasting reduces the allergenicity of hazelnut in individuals with a birch pollen allergy and reactivity to raw hazelnut. Thermal processing may reduce the allergenicity of the PR-10 protein in hazelnut and almond in vitro. The majority of the in vitro studies investigating the allergenicity of nonspecific lipid transfer proteins (nsLTPs) and seed storage proteins in hazelnut, almond, cashew nut, Brazil nut, walnut, pecan nut and pistachio nut show heat stability towards different thermal processing methods.
Conclusion: Thermal processing may reduce allergenicity of PR-10 proteins in hazelnut and almond, in contrast to nsLTPs and seed storage proteins. This has important implications for source materials used for IgE testing and food challenges and diet advice.

Sincerely,
Phil Lieberman, M.D.

AAAAI - American Academy of Allergy Asthma & Immunology