CSPI Quorn Complaints
Center for Science in the Public Interest

Medical Evidence Shows that Quorn Causes Adverse Reactions

The first evidence that Quorn causes severe vomiting and stomach ache came in 1977 from a clinical study conducted by the developer of Quorn. That research was never published. In subsequent years, more research has demonstrated that Quorn causes gastrointestinal and other adverse reactions, including hives and breathing difficulties. These are the key studies:

RHM (unpublished 1977-78 study)

This controlled clinical study was conducted by the company that developed Quorn. Ten percent of the 200 subjects who ate Quorn experienced nausea, vomiting, or stomach ache, compared to five percent of 100 subjects in a control group. This is the first known study that demonstrated that Quorn could cause adverse effects. It appears that when Marlow Foods notified the Food and Drug Administration that Quorn should be considered "Generally Recognized As Safe," it did not acknowledge the existence or results of this study. It is not known whether the study was submitted to the British government when Quorn was first used. The study was obtained from a food additive petition filed with the FDA.

Udall et al. (Am J Clin Nutr. 1984;40:285-292)

This study did not find any problem in 100 college students who ate Quorn for 30 days. However, co-author Nevin Scrimshaw in 2003 told the U.S. Food and Drug Administration that "I have no doubt from the evidence currently available that the fungal product being marketed as Quorn, and that is causing an alarmingly high frequency of allergic reactions, some of them quite serious, is not the same product we tested. He added: "I am appalled that this material is allowed to stay on the market."

Tee et al. (Clin Exper Allergy. 1993:23:257-260)

This study was the first to appear in the medical literature and indicated possible safety problems with Quorn. The study involved 10 Britons who believed that Quorn caused vomiting or stomach ache. The study used classic allergy tests (like the skin-prick test) to assess the patients. There were weak indications that Quorn was allergenic, but the test methods used are considered insensitive and not highly accurate. The subjects were not fed Quorn foods, which might have elicited adverse reactions.

Katona SJ, Kaminski ER. (J Clin Pathol. 2002 Nov;55(11):876-877)

This letter from British researchers reported sensitivity to Quorn in a mold-allergic patient.

Hoff et al. (J Allergy Clin Immunol. 2003 May;111(5):1106-1110)

These European researchers proved that Quorn caused an asthmatic reaction in a patient. They identified the particular protein that caused the allergic reaction. This paper is important.

Jacobson, M.F. (Allergy. 2003 May;58(5):455-456)

This letter, submitted by the executive director of the Center for Science in the Public Interest, described the adverse reactions reported by the first 284 people who contacted CSPI. It was the first item in the medical literature that indicated that Quorn caused widespread reactions, including vomiting, stomach ache, hives, and breathing difficulties.

Van Durme P, Ceuppens JL, Cadot P. (J Allergy Clin Immunol. 2003 Aug;112(2): 452-454)

Belgian researchers identified a young woman who suffered a severe anaphylactic-type allergic reaction after her first ingestion of Quorn. Skin prick tests were highly positive with Quorn extracts. The researchers deduced that Quorn can be cross-reactive with inhaled mold spores.

Jacobson, M.F. (Am J Med 2003 Sep;115:334)

This letter, submitted by the executive director of the Center for Science in the Public Interest, described the adverse reactions received by CSPI. The letter cites a survey showing that mycoprotein is more likely to cause adverse reactions than shellfish, milk, peanuts, and other common food allergens.

Sandhu M. (AllergyCases.org)

This case report describes a 14-year-old boy who had a reaction within two minutes of eating Quorn imitation chicken. The symptoms included throat irritation followed by itchiness, difficulty breathing, and swelling of the lip, tongue, eye, and laryngeal edema. A positive skin test demonstrated a sensitivity to small amounts of Quorn (and other molds).