Self-reported adverse reactions associated with mycoprotein (Quorn-brand) containing foods

Background Mycoprotein, which is produced by a mold and is the basis of Quorn-brand meat substitutes, is a novel cause of allergic and gastrointestinal reactions, but little information has been available on its associated symptomatology. Objective To describe the nature and frequency of adverse reactions to mycoprotein. Methods Self-reports of adverse reactions to mycoprotein were collected via a Web-based questionnaire (www.quorncomplaints.org) and then analyzed. Results Analysis of 1,752 adverse reactions found that Quorn products caused allergic and gastrointestinal symptoms, with some people experiencing both. Allergic reactions, including urticaria and anaphylaxis, occurred within 4 hours of consumption in 312 people. Of those reactions, 45.8%, 1 fatal, began within 1 hour of exposure. Of those 312 individuals, 188 (60.3%) reported repeated reactions after repeated consumption of Quorn, and 2 people experienced 8 reactions (13 people did not say whether they experienced more than 1 reaction). Quorn foods caused gastrointestinal symptoms, including emesis and diarrhea, within 8 hours of consumption in 1,692 people. Of the gastrointestinal symptoms, 66.6% occurred 46 to 180 minutes after consumption of the products. Symptoms ranged from mild nausea to emesis severe enough to warrant medical attention. Conclusion Mycoprotein may be causing numerous and sometimes life-threatening allergic and gastrointestinal reactions. The acceptance in the food supply of this nonessential ingredient deserves reconsideration.