The Yellow Knight Fights Back: Toxicological, Epidemiological, and Survey Studies Defend Edibility of Tricholoma equestre

Abstract

Rhabdomyolysis, a condition associated with the consumption of Yellow Knight mushrooms (Tricholoma equestre), was first reported in 2001. In response, some countries began to consider the mushroom as poisonous, whereas in others it is still consumed. In the present study, a nationwide survey of Polish mushroom foragers (n = 1545) was conducted to estimate the frequency of T. equestre consumption. The epidemiological database on mushroom poisonings in Poland was analyzed from the year 2008. Hematological and biochemical parameters were followed for a week in 10 volunteers consuming 300 g of molecularly identified T. equestre. More than half the foragers had consumed T. equestre at least once in their lifetime and a quarter had consumed it consecutively. The frequency of adverse events was low and no rhabdomyolysis was reported. The toxicological database indicated that mushrooms from the Tricholoma genus caused poisonings less frequently than mushrooms with well-established edibility and not a single case of rhabdomyolysis has been reported within the last decade. The volunteers consuming T. equestre revealed no hematological or biochemical alterations and no adverse effects were observed. The findings of this study support the view that T. equestre is edible if consumed in rational amounts by healthy subjects.

Comment on “Study of biological activity of Tricholoma equestre fruiting bodies and their safety for human”

“…Finally, the hypothesis that T. equestre causes rhabdomyolysis is contradicted by observations in studies employing volunteers consuming this mushroom [6,9]. The foragers that consumed 300 g of molecularly identified, fried specimens of T. equestre showed no changes in hematological and biochemical markers, including aspartate and alanine aminotransferase, bilirubin, and creatine kinase (CK) [9].…”

“…It is still considered edible and widely consumed in regions such as Poland [8]. As shown in a recent study, more than half of mushroom foragers in this country have consumed T. equestre at least once in their lifetime [9]. This questionnaire survey and additional analysis of Polish registry of mushroom toxicity demonstrate that no rhabdomyolysis was reported in the last decade and that only mild gastrointestinal effects were noted, at a lower frequency than for other well-established edible wild mushrooms, such as Macrolepiota procera and Imleria badia [10,11].…”

Macrofungi: A review of cultivation strategies, bioactivity, and application of mushrooms

“…It was reported that the ingestion of yellow knight mushrooms (Tricholoma equestre) could cause rhabdomyolysis (Bedry et al, 2001). After extensive and numerous human trials on T. equestre intake, however, no hematological or biochemical alterations and no other adverse effects were observed (Klimaszyk & Rzymski, 2018). Therefore, macrofungi toxicity and safety merit consideration.…”

Toxic Potential of Traditionally Consumed Mushroom Species—A Controversial Continuum with Many Unanswered Questions

“…L. edodes also displays cholesterol-lowering properties [ 36 ] indicating that, again, the balance of beneficial and potentially hazardous effects of a species has to be taken into consideration when assessing its suitability for consumption. Hitherto, the causative agents of these effects often remain to be determined, and scientists have reached contradictory conclusions on edibility, especially regarding T. equestre [ 15 , 37 ]. Overall, the existing literature, not only on T. equestre but edible mushroom toxicity in general, is relatively scarce and, for obvious reasons, double-blind experiments to study the issue are virtually impossible.…”

“…However, the long tradition of consumption without previous reports of toxicity also triggered suggestions of there being no need to change recommendations [ 45 ]. The issue has become even more controversial after a new Polish study [ 37 ] that reported no harmful effects on humans and suggested that T. equestre would be edible if appropriate care would be taken, that is, the mushroom would be consumed in rational amounts by healthy subjects. The authors suggested that the toxic effects could have been caused by individual susceptibility, consumption of morphologically similar species, or by repeated digestion of mushrooms in general.…”