"Amanita phalloides 1" by Archenzo - Own work. Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:Amanita_phalloides_1.JPG#/media/File:Amanita_phalloides_1.JPG
This is not a mushroom that belongs on anyone’s dinner plate.  “Amanita phalloides 1” by Archenzo – Own work. Licensed under CC BY-SA 3.0 via Commons: https://commons.wikimedia .org/wiki/File:Amanita_phalloides_1.JPG#/media/File:Amanita_phalloides_1.JPG

The following story is enough to make any mushroom hunter shake his or her head.  Read on…

It’s often reported that ancient Homo sapiens learned to distinguish between edible and poisonous species through trial and error.  Encounter an unfamiliar plant, eat the unfamiliar plant, await any negative symptoms… proceed accordingly.  If the experimenter lived, the tribe celebrated.  If the experimenter croaked, well then… God rest the poor chap’s soul.

Of course, this “trial and error” theory is just that a theory that has made its indelible mark in biology, history, and nutrition text books all across the world.

Perhaps it is true that our species was once an unobservant lot who traversed the continents, hastily sampling plants and mushrooms out of hunger and desperation.

Maybe… maybe not.

Perhaps, in our evolutionary infancy, we really were ignorant of the land, completely unaware of the overarching commonalities between various species of plants, mushrooms, and animals commonalities that could apply to species in new territories.

Maybe… maybe not.

Whatever the truth, we now have brand new evidence to support the notion that… yes indeed… humans will resort to trial and error when trying to figure out what’s edible and what’s poisonous.   The journal Wilderness and Environmental Medicine recently published an article entitled “A Case Study: What Doses of Amanita phalloides and Amatoxins Are Lethal to Humans?” (1), telling the story of a man who put this theory to the test by willingly consuming unidentified mushrooms.

For those unfamiliar with wild mushrooms, let me explain some of the terms in the study’s title.  Amanita phalloides, commonly referred to as the death cap mushroom, is one of the deadliest mushrooms in the world.  It contains a class of compounds known as amatoxins that inhibit an enzyme in our bodies known as RNA polymerase II.  Ingestion of Amanita phalloides and its amatoxins can lead to liver and kidney failure.  The end result, if not treated immediately, can be death.  For a detailed description of the death cap mushroom, click here.

Now, it’s hard to imagine that any man or woman would willingly participate in this sort of study.  Sign me up for a meal of death caps… no thanks!  However, when a 61-year-old man takes it upon himself to precariously eat unidentified mushrooms, including death caps… well, then… what scientist wouldn’t want to publish the results in a paper?

According to the researchers:

“A 61-year-old man weighing 67 kg was admitted to the emergency room with fatigue, abdominal pain, nausea, vomiting, and diarrhea.  In obtaining the patient’s history, he said he had collected several mushrooms that differed from those he typically gathered, but he was not quite sure if they were edible.

The patient tried a dangerous test on himself to determine whether the mushrooms he had collected were poisonous.  He removed the stems of 2 mushrooms, cooked only the caps on the stove, and ingested them.  He told the household that if nothing happened to him, they could eat the remaining mushrooms together the next day.

At approximately [4:00 am], 8 to 9 hours after he ingested the mushrooms at approximately [7:00 pm], he woke up with nausea, vomiting, stomachache, and diarrhea.  The patient realized that he was poisoned from the mushrooms he had eaten; he drank some water and vomited a few times in an effort to clean his stomach.  He thought that he did not need to go to a hospital, but approximately a day after the poisoning, he was persuaded by his family and brought to the emergency department.

The patient was then admitted to the internal medicine unit after having been diagnosed with mushroom poisoning.  A consultation was requested from the clinical pharmacology and toxicology unit, which had experience with mushrooms.  Following up the history taken by the specialist, the mushroom specimens at the patient’s home were examined and identified as A. phalloides mushroom.”

Before I proceed any further, I’ll provide this disclaimer:  do not try this at home!

Now, you’re probably wondering what happened to the man.  To provide some context, it’s important to first understand the mechanisms behind mushroom poisoning.

Poisoning by amatoxin-containing mushrooms, like the death cap, is different than poisoning by other toxic mushrooms.  For example, ingestion of the jack o’lantern mushroom (Omphalotus olearius), which contains the toxin illudin S, results in severe cramps, vomiting, and diarrhea usually within a few hours after ingestion.  Symptoms can persist for a few days, though the patient almost always fully recovers.

On the other hand, poisoning by amatoxin-containing mushrooms can be divided into 3 stages.  A latent stage of 6-12 hours is characterized by an asymptomatic phase.  Eventually, the patient will experience nausea, vomiting, cramps, and diarrhea.  The second stage is characterized by improvements in physical symptoms.  However, even though the patient may seem to be improving, ongoing liver damage is occurring.  This stage can last 2-3 days.  In the third and final phase, liver and kidney damage become clinically apparent, potentially leading to irreversible liver failure.  Death may occur in 3-7 days.

The researchers reported that this man cooked and consumed 2 caps of Amanita phalloides.  Upon admission to the emergency room, he was treated with activated charcoal for 3 days, and intravenously rehydrated with sodium chloride and dextrose.  He was also given Penicillin G in continuous doses for 72 hours.  Though his liver enzyme values (aspartate aminotransferase and alanine aminotransferase) increased for 4 days (a sure sign of liver damage), they began to decline at hour 96.  The man was discharged after 9 days and was considered fully recovered by day 15.

Lucky man.  Not all who eat the death cap live to tell the tale…

Back to the study’s title.  What doses of Amanita phalloides and amatoxins are lethal to humans?  Because the patient’s liver enzymes increased to levels just below the threshold associated with mortality (as assessed by previous studies), the researchers concluded that consumption of more than 2 medium-sized caps of Amanita phalloides, which equates to approximately 50 grams of fresh material, can be deadly.  The researchers discovered that the man consumed approximately 21.3 mg of amatoxins contained within the 2 caps, and they concluded that oral intake of more than 0.32 mg/kg of amatoxins may be lethal.

Lots of numbers, I know.  What does all of this mean for hungry human foragers?  Simply put  no amount of Amanita phalloides should be considered safe for consumption.

You see, the researchers are not stating that 2 caps or less of Amanita phalloides are safe to consume.  Numerous factors contribute to the effects of mushroom poisoning on humans, including the health of the patient, his or her susceptibility or predisposition to liver injury, and variation in the concentration of amatoxins from various locales.  Even the smallest amount may be enough to kill a human.

When it comes to wild mushroom hunting, the 61-year-old man in this particular study is a perfect role model of what not to do.  (Okay, you gotta give it to him for not feeding the mushrooms to his family!  Wise move.)  However, there are much better ways to accurately identify wild mushrooms… the trial and error method surely making the bottom of the list.

Above all, I highly recommend joining a mushroom club.  If you live in North America, check out this list of clubs affiliated with the North American Mycological Association.  An extremely wise habit is to cross-reference your mushrooms with several resources, and always be absolutely positive with your identification before ingesting wild mushrooms in any form.  Your safest bet is to have an expert identify, or confirm the identification of, your specimens.  A quick online search will yield local mycologists as well as online forums to assist in the identification process.

Scared?  Don’t be.  Mushroom hunting is an incredibly rewarding activity.  Nature demands a certain level of intention, responsibility, and care when harvesting from the land.  Ultimately, it seems that the trial and error method is probably best left practiced in the supermarket.  (Though I encourage you to stay clear of the chip aisle!)

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