Mulberry is a plant of the family Moraceae and genus Morus. Allergic sensitization to mulberries has been reported by people across the globe. In the articles reporting mulberry allergy, the reactions included respiratory allergy, airborne contact urticaria, anaphylaxis, oral allergy syndrome, and food-induced urticaria.

The allergens identified thus far in mulberries were the following: pathogenesis-related PR10 proteins, with sequence identity to Bet v 1 from birch, LTP 1 protein with identity with LTPs from Rosaceae family plants, panallergens groups, and also ubiquitin-like protein and cystatin-like protein. The two latter proteins account for cross-reactions with Parietaria Judaica and Olea europaea. Such large cross-reactivity warrants to pay particular attention to the risk of systemic reactions to foods, particularly in subjects sensitized to birch, Parietaria, or olive pollens.

The study concluded through its findings that the increasing use of mulberry as a food product, which is encouraged by its remarkable antioxidant power, exposes sensitized patients to possible reactions after ingesting foods, dietary supplements, or nutraceuticals containing mulberry. Mulberry allergenicity can vary according to the processing methods used since some allergens are thermostable and others lose their reactivity during heating.

Reference: https://clinicalmolecularallergy.biomedcentral.com/articles/10.1186/s12948-020-00116-7

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