Oh, the lovely bezoar. Does it sound familiar to you Potter fans? Pronounced BE-zoar, some of you may remember stumbling over this word when Harry Potter shoved the so-called stone antidote into the throat of a choking, poisoned Ron Weasley. 

“A bezoar is a stone taken from the stomach of a goat and it will save you from most poisons.” – Severus Snape (Rowling, 2014).   

While this moment of high intensity is shrouded in magical fiction, its concept is not entirely made up (bloody brilliant, that JK Rowling).  Bezoars form in the gastro-intestinal tracts of some animals and humans (Fig. 1) and have historical significance dating back to the Middle Ages (Do Sameiro Barroso, 2013). In fact, they might save you from arsenic poisoning, but more on that later.  

Biology 

The bezoar is an undigested conglomerate of either hair (trichobezoar), fibrous matter (phytobezoar), or both (trichophytobezoar) (Gore, 2008). They are found in the stomachs and sometimes small intestines of a wide range of animals, from monkeys and goats, to porcupines and fish (Do Sameiro Barroso, 2013). The outsides of these compact masses are hard, and their insides contain heavily packed, intertwining thick fibers (Mori & Sforzi, 2013). They also vary in size, with one Spanish bezoar coming in at a whopping eight pounds (Do Sameiro Barroso, 2013).  

If you own a cat, you might have come across a trichobezoar. Fun fact, hairballs are just the common term for the mass of hair, food, and dirt that gets coughed up now and then by our precious felines (Stregowski, 2021). Me-ow. And it’s not just cats, these types of bezoars can also be found in humans (Shah et al., 2021). That’s right. Ladies and gents, I present to you the human hairball: (Fig. 2) Unlike your cat, you will not be coughing one of these bad boys up any time soon. Most human bezoar’s can be removed endoscopically, laparoscopically, or dissolved by cola (Shah et al., 2021).  

The phytobezoar (arguably less gross) is often associated with a high fiber diet (poorly digested fruit and vegetable skins) and can be found in domestic animals such cows, sheep, goats, and horses (Mori & Sforzi, 2013). In humans, ingesting a high quantity of the persimmon fruit can result in the fruit’s particles coagulating in gastric juices and trapping materials within to form a phytobezoar (Eisenberg & Levine, 2008). For our goat and porcupine varieties, different types of fibrous roots, tubers, and nettle make up these incidental masses (Mori & Sforzi, 2013).  

Arsenic 

Now that we have the basics down, what about arsenic poisoning? There is no conclusive answer to this question so… maybe. Gustaf Arrhenius and Andrew A. Benson of the Scripps Institution of Oceanography demonstrated that a bezoar in arsenic solution effectively absorbed all the arsenic (Do Sameiro Barroso, 2013). For you biochemists, arsenic contains two toxic compounds: arsenate and arsenite. In the experiment, arsenate is exchanged with the bezoar’s phosphate via ion exchange, and arsenite binds to sulphur compounds found in the degraded hair particles of the bezoar (Do Sameiro Barroso, 2014). Pretty cool, but peer-reviewed research has yet to confirm or deny this finding (Fabián, 2019). In other words, do not try this at home, kids. 

History 

As interesting as the biology might be, the bezoar’s history might be weirder.  Bezoars, an Arabic medicinal antidote harvested from sacrificial goats, entered the European market in 12th century. Along with the unicorn horn, they were administered to treat stomach pain, stroke, fever, old age (ah yes to be young again), poison, and venomous bites.  Many maladies plagued Europe at this time, and doctors with few alternatives turned to the bezoar. To prepare said antidote, the stone was scraped into a powder, added to liquid (usually wine), and given to the patient (Do Sameiro Barroso, 2013). Makes that cherry-flavored cough syrup sound not so bad, huh? 

Bezoars were rare, and their price only grew with demand. One bought by the wife of a wealthy banker is said to have cost 130 ducats (roughly $19,347 today). If one was rich enough to afford a genuine bezoar (and had an unhealthy taste for interior design), there were plenty of decorative options to display the stone.  The stones were said to bring good fortune and, of course, aid in any instance of poisoning.  The nobility and wealthy displayed their bezoars in silver, gold, or with precious stones (Fig. 3,4). A bezoar even graced the crown of Queen Elizabeth I (Do Sameiro Barroso, 2013).  Such unbelievable prices eventually led to counterfeits entering the market. Ironically, some of these fake bezoars contained toxic cinnabar, quicksilver (mercury) and antimony (Do Sameiro Barroso, 2013).   

The bezoar fad came in hot, but burned out quickly by the end of the 19th century. And critics abounded. 

 “I found the poor cook on all fours, going like an animal, his tongue out of his mouth, his eyes and his face flaming red … I made him drink about half a sextier of oil, thinking to save his life; but it was of no service …he died miserably, crying out he had better have died on the gallows.” 

 -Ambrose Pare, Ambroise Pare and His Times, 1510-1590. 

It may sound like something out of Game of Thrones, but that gruesome scene describes an actual experiment led by Ambrose Pare, France’s top battle–field surgeon of the 16th century.  When presented with a Spanish bezoar, Monsieur Ambrose, a skeptic, put the bezoar’s antidotal powers to test on a poor convict. It obviously did not go well. Eventually, enough evidence and scrutiny led to the end of the bezoar golden age (Do Sameiro Barroso, 2013). While modern science does not recommend ingesting a bezoar, you can still buy them today, and they are used in some Chinese medicines as an anti-inflammatory (Fabián, 2019).  

Prevalence/Today 

While bezoars can form in perfectly healthy individuals, they are more commonly found in those with pre-existing conditions with the GI tract or those with mental illness (such as schizophrenia). As mentioned previously, they often require endoscopy for sufficient removal or sometimes even Coca-Cola to dissolve the mass. They’re not very common, with studies finding only a 0.0125 to 0.068% prevalence in adults (Shah et al., 2021). So how scared do you need to be in terms of forming your own bezoar? Ehh, not really. For now, let us leave them to the magical world of Harry Potter and the occasional kitty hairball.    

References: 

Do Sameiro Barroso, M. (2014). The bezoar stone: a princely antidote, the Távora Sequeira Pinto Collection-Oporto. Acta medico-historica adriatica : AMHA, 12(1), 77–98. 

Do Sameiro Barroso, M. (2013). Bezoar stones, magic, science and art. Geological Society of London Special Publications. 375. 193-207. 10.1144/SP375.11. 

Fabián, O. (2019). The allure of the bezoar endures. MRS Bulletin 44, 968.  

Gore, S., Richard M., Levine, M. (2008). Textbook of Gastrointestinal Radiology. Elsevier – Health Science, 2021. ScienceDirect, Accessed 26 Sept. 2021.  

Mori, E. & Sforzi, A. (2013). Structure of phytobezoars found in the stomach of a crested porcupine, Hystrix cristata L., 1758. Folia Zoologica -Praha- 62, 232-234.  

Rowling, J. K. (2014). Harry potter and the philosopher’s stone. Bloomsbury Childrens Books. 

Shah, M., Wan, D. Q., Liu, Y., & Rhoads, J. M. (2021). Gastric Bezoar: Retrieve it, Leave it, or Disbelieve it?. Journal of pediatric gastroenterology and nutrition, 72(2), e31–e36.  

Stregowski, J. (2021). “What Can I Do to Prevent Bezoars In Cats?” The Spruce Pets, https://www.thesprucepets.com/glossary-term-bezoar-3385454.