The Dangers of Quorn Products

If you frequently eat meat substitutes, look out for Quorn products, or you may suffer their not uncommon and sometimes deadly side effects.


Mycoprotein, the novel ingredient in Quorn-brand frozen meat substitutes that’s made from processed mold (Fusarium venenatum), can cause serious and even fatal allergic reactions.

Though the manufacturer’s (Marlow Foods) advertising and labeling implies that the product is “mushroom protein” or “mushroom in origin,” the mold (or fungus) from which it is made does not produce mushrooms. Rather, the mold is grown in liquid solution in large tanks.

It has been used in the United Kingdom since the 1990s and has also been sold in continental Europe. Quorn products have been marketed in the United States since 2002 and in Scandinavia, Australia, and New Zealand more recently. The chunks of imitation meat are nutritious, but the prepared foods in which they are used may be high in fat or salt.

Several percent of consumers are sensitive to Quorn products, resulting in vomiting, nausea, diarrhea, and, less often, hives and potentially fatal anaphylactic reactions. Many people have gone to emergency rooms for treatment of Quorn-related reactions. In 2013, an 11-year-old boy who had asthma died after eating a Quorn Turk’y Burger.

A survey in the United Kingdom sponsored by the Center for Science in the Public Interest (CSPI) found that the percentage of consumers sensitive to Quorn is probably as great as, or greater than, the percentage sensitive to soy, milk, peanuts, and other common food allergens. The British and American governments acknowledge that people are allergic or intolerant to Quorn foods, but so far have rejected CSPI’s recommendations to bar the use of mycoprotein or require Quorn foods to bear a label warning of possible severe adverse reactions. (In fact, when Quorn-containing “vegetarian” products are served at restaurants, cafeterias, and other foodservice locations, there is no label to inform consumers that they are eating Quorn foods.)

CSPI urges consumers to avoid Quorn products and urges natural-foods retailers like Whole Foods not to sell this product that is dangerous to sensitive individuals.

Reactions to Quorn products

I developed a bad stomachache, headache, and nausea and vomiting after consuming 2 Quorn patties for lunch and part of a bag of Quorn cubes a few hours later…. The stomachache started shortly after eating the products but I did not make the connection until I began vomiting a number of hours later. I will never eat this product again because I believe the symptoms were due to the Quorn products. I also had a very unusual taste in my mouth with [belching] after I ate Quorn and it didn’t go away until after I vomited numerous times…. I was very ill and I was alone.

– P.H. Boulder, Colorado

On 3 separate occasions I suffered severe, sudden nausea followed by a few hours of violent vomiting after eating Quorn products. I was out for dinner and had to make my journey home while vomiting violently every few minutes.

– C.J. Glasgow, United Kingdom

About 1.5 hours after eating the meatballs…I felt a tingling sensation throughout my entire body. I broke into a heatflash…so bad I was dripping wet from sweat. My shirt was soaking wet. My entire insides felt like they were being turned inside out. 2 hours after eating the product I started vomiting violently. In all…I had 4 episodes of intense vomiting & 2 bouts of diarrhea.

– D.A. Leola, PA

I ate one portion of Quorn meat substitute. I became VERY sick, nausea and vomiting (several times). I assumed that I had a stomach virus. Later that night I realized that I had eaten something earlier that I had never eaten before. I looked it up on my laptop and saw that others had been similarly sickened. I threw out the remainder of the box. I have never eaten any Quorn product again, and I have been amazed that the products are still on the market. I was SOOOO sick.

– A.W. Durham, NC

I have had a violent reaction to eating Quorn on three occasions (only in retrospect identifying Quorn as the common element). Symptoms came on between three and five hours after ingestion. They started as a headache and rapidly turned into a migraine type attack, followed quickly by diarrhea and then simultaneous vomiting. This would last for a couple of hours. I then found that I needed to sleep for sometime and when I woke suffered from what I can only describe as a hangover. The effects of my reaction took about 24 to 36 hours to clear… My reaction was not unlike Salmonella poisoning (which I have had) and was put down to that. It was this attack made me realize it was Quorn as I ate an identical meal to my sister, who was unaffected.

– T.B. London, UK

Consumers who believe they have been sickened by Quorn foods may file an adverse-reaction report with the Center for Science in the Public Interest.