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.