Into the Wild and other Poisonous Plant Fables

Note: This is an updated version of this article, addressing the two additional hypotheses that Krakauer has presented since I first posted this piece. In September of 2015 he published an article in the New Yorker proclaiming that he had new evidence that "closed the book" on the cause of McCandless's death: he died from lathyrism, a condition caused by a chemical known as ODAP, ingested in great quantity over a prolonged period by malnourished people. The evidence supporting this proposition was essentially nonexistent (as with his previous 3 hypotheses), and Krakauer recanted hypothesis 4 in February of 2015, replacing it with an equally unsupported hypothesis: that McCandless died from a chemical called L-canavanine. Yes, that makes a total of five different hypotheses for how eating a wild plant caused Chris McCandless to starve to death. The credibility of each hypothesis alone is highly suspect, but taken in sum total they suggest the desperation and myopia that accompany all prejudice.


About ten years ago, a man approached me after a presentation that I had given on wild edibles. Obviously quite agitated, he stuttered a few syllables before launching a frantic diatribe, “You need to warn people that there’s some edible plants that look exactly like deadly poisonous plants, and they grow side by side, and nobody can tell them apart. Nobody! Not even an expert!

I paused, in a mild state of shock, before responding, “That’s not really true. Some plants might . . . .”

“It is true,” he interrupted. “Books tell people they can eat these plants, but they don’t tell them that there’s deadly poisonous plants that look exactly the same. It’s like playing Russian roulette.”

Of course, it isn’t true, but the fear of wild plants runs very deep in Western civilization. While it certainly is true that people can poison themselves with wild vegetation, the fear that we attribute to plants is monstrously out of proportion with the actual danger they pose. Like many profound and unexamined fears, this one breeds irrationality, causing many people to suspend all logic and refuse to participate in rational discourse.

Another time, some friends and I stood at a beach, stuffing our faces with serviceberries, and two children, a brother and sister, took interest. As they were about to partake, their father intervened. From his lawn chair fifty feet away, he warned them that they’d poison themselves and die if they ate “those berries.” His son piped in, “But Dad, I already ate some and they’re really good!”

His father didn’t budge. A little later, the children passed by again and surreptitiously asked, “Are they really poisonous?”

As I shoveled in another handful, I smiled and asked, “What do you think?” They giggled back, recognizing the absurdity of their father’s logic: “These people are eating something they enjoy very much; it must be deadly poisonous.”

We are spellbound by the story of someone mistaking a poisonous plant for an edible one and dying from the error. It is a magnetic motif with a suite of admonitions that our society finds useful: don’t stray too far from the beaten path; what civilization has given you is better than you realize; Nature cannot be trusted. Every culture builds its own propaganda to promote stability. An important aspect of this propaganda is fables—stories made up to teach particular lessons. But since we have trouble finding examples of wild plant poisonings, we fabricate the story again and again.

The Poison Plant Fable assumes many forms. Several foraging-death urban legends are commonly told, even among foragers. When the world-famous wild food author Euell Gibbons died of a ruptured aortic aneurysm, people immediately began fabricating stories about his death being caused by eating a wild plant. These falsehoods were more widely believed than the truth and are still commonly circulated today. I am frequently confronted by people who, believing this Euell Gibbons fable, present it as “proof” that foraging is stupid and dangerous. In her Encyclopedia of Country Living (1994), Carla Emery uses this story in an attempt to terrify her readers away from foraging:


Even Euell Gibbons, who wrote a whole series of books extolling the glories of wild food foraging, finally goofed and tried the wrong wild leaf in his lunch. That’s how he died. (Emery, 1994, p. 401)


The ignorant fear-mongering of people who have internalized this fable is a disservice to everybody.


Into The Wild: Another Poisonous Plant Fable?

At workshops or presentations that I have given over the last fifteen years, I have been repeatedly asked about Jon Krakauer’s book Into The Wild, which is probably the most eloquent and captivating rendition of the Poison Plant Fable yet produced.

Into The Wild is about an emotionally embattled young man named Chris McCandless who left his affluent upbringings behind, renamed himself Alex, and wandered the West. His decaying body was found by a moose hunter in Alaska on September 6, 1992. Through an autopsy, medical examiners determined that McCandless had starved to death, and all evidence pointed clearly to that conclusion. But the Poison Plant Fable proved irresistible to Krakauer, who first wrote about the tragedy in “Death of an Innocent,” (a January 1993 article in Outside magazine). He conjectured that Chris had died by poisoning when he mistook the wild sweet pea Hedysarum mackenziei for the “wild potato” Hedysarum alpinum. But since Chris had clearly starved to death, Krakauer had to reach further, positing that McCandless was “laid low” by the poisoning, and thus unable to feed himself. Since we have all internalized the Poison Plant Fable, this unlikely and scientifically unsupported explanation for Chris’s death was immediately and widely accepted as fact.

But there is no evidence that Chris McCandless ever ate the seeds of H. mackenziei. Krakauer doesn’t try to provide such evidence; he simply tells us that the two plants grow beside each other and are “very difficult to distinguish.” Provided with these facts, most people immediately conclude that McCandless mistook wild sweet pea for wild potato. Like Krakauer, they don’t need any evidence because the Poison Plant Fable says that it happens this way. But how plausible is this?

An important component of the Poison Plant Fable is the insistence that “even experts” have trouble identifying edible plants. In Into The Wild, Krakauer writes, “Wild sweet pea looks so much like wild potato that even expert botanists sometimes have trouble telling the species apart” (p. 191). Actually, Hedysarum alpinum and H. mackenziei can be consistently, reliably, and easily told apart by any person who has become familiar with them. Despite Krakauer’s insistence that the veins on the underside of the leaflets are the only reliable characteristic distinguishing them, there are numerous features of the two plants that are different. Foragers can learn to distinguish these plants by their roots alone (Schofield, 1989).

Krakauer proposed that, after more than a month of collecting H. alpinum safely, McCandless suddenly couldn’t recognize the plant and accidentally ate a significant volume of H. mackenziei seeds. This is quite improbable. After weeks of collecting wild potato and successfully distinguishing it from wild sweet pea, Chris would have developed an excellent search image for both plants. Misidentification at this point would be about as likely as a man making love to the wrong woman and not noticing.

The second flaw in Krakauer’s poisoning hypothesis is the fact that H. mackenziei, the plant that supposedly poisoned Chris McCandless, is not poisonous. Although Tanaina Plantlore, the field guide that Chris was using, says that the plant is “reported to be poisonous,” this is actually a rather insignificant statement. Myths of toxicity are a universal aspect of human culture, and I can find printed references reporting about two-thirds of all wild edibles to be poisonous. Indeed, some plants called poisonous or inedible in Tanaina Plantlore were regular food items for other Native American tribes.

Krakauer confidently calls H. mackenziei “poisonous” in his Outside article. When he elaborates in Into The Wild, he admits that “accounts of individuals being poisoned from eating H. mackenziei are nonexistent in modern medical literature” (p.191), but he supports his claim with one highly questionable report from 1848.

In the wake of the Chris McCandless case, extensive laboratory analyses of the roots, seeds, flowers, leaves, and stems of H. mackenziei have been conducted. These tests have turned up no alkaloids or toxins of any kind (Treadwell and Clausen, 2008). These authors conclude that there is no credible chemical, historical, or ethnobotanical basis for the anecdotal belief that H. mackenziei is toxic. They believe that the wild sweet pea is nontoxic and has not been traditionally used simply because of the smaller size of its roots.

The hypothesis that Chris McCandless died from eating H. mackenziei seeds is supported by no evidence and has absolutely no factual basis.

Krakauer’s Second Hypothesis

Forced to recognize the weakness of his original poisoning theory, Krakauer discarded this explanation and proposed a new one: that Chris was poisoned by the seeds of H. alpinum—the plant that he thought he was eating. Now, the story went, Chris hadn’t eaten the wrong plant, he had eaten the wrong part of a plant, and this caused him to starve to death.

We know from McCandless’ journals and photos that he actually had eaten H. alpinum seeds. However, evidence for toxicity of these seeds was entirely nonexistent at that time. Krakauer himself points out that “the seeds of H. alpinum have never been described as toxic in any published text: an extensive search of the medical and botanical literature yielded not a single indication that any part of H. alpinum is poisonous” (p. 191). Yet Krakauer’s second hypothesis wasn’t just that “wild potato” seeds were poisonous; it required them to be poisonous in a very specific and unusual way: by promoting starvation through inhibiting digestion and metabolism.

Chris McCandless clearly starved to death, and Krakauer has never denied this—he just argues that eating a wild plant made him starve to death. At face value, this is a very odd proposition. Last time I checked, death by starvation was caused by not eating enough food for a long time. Krakauer identified an alkaloid called swainsonine as a hypothetical agent of starvation—although he was apparently, like me, unable to find a single reported case of swainsonine poisoning in humans.

Krakauer argues this improbable case with a carefully crafted series of specious arguments, rash assumptions, and illogical conclusions by which the readers of Into The Wild are misled to believe that this hypothesis has somehow been verified. As soon as it is suggested that wild potato may contain alkaloids, the plant is treated as if it is known to contain an alkaloid. As soon as he states that alkaloids may be toxic, they are treated as toxins. We are told that alkaloids may be localized in one part of the plant, and that the seeds are the most likely site for this localization. When we are then told that “preliminary testing” indicated that the seeds contain “traces of an alkaloid,” we are beguiled into the totally unsupported conclusion that wild potato seeds contain toxic alkaloids despite their roots’ edibility. (Thorough later testing contradicted these preliminary results; but Krakauer didn’t change his story until the media exposed this fact more than ten years after Into The Wild was published.)

We are then told that there is “a strong likelihood” that the (non-existent) alkaloid is swainsonine. This claim is ridiculous—any reasonable assessment would place the likelihood as “very small.” Hedysarum alpinum and H. mackenziei are common, widespread range plants that are considered good forage for livestock (Larson and Johnson, 2007). If they contained swainsonine, this would almost certainly be well known, since virtually everything we know about this chemical is due to its toxic effect on grazing livestock, and a great deal of research has gone into identifying which legumes contain it. After thus misleading the readers, Krakauer proceeds as if Hedysarum seeds do contain this alkaloid, and selectively discusses a few of the physiological effects of swainsonine poisoning in livestock.

The above is not an explanation; it is a meaningless string of unverified assumptions. It is not a theory; it is an untested progression toward a predetermined conclusion. It does not withstand even cursory examination under the scientific method. Yet it fulfills the Poison Plant Fable.

Dr. Thomas Clausen, a biochemist at the University of Alaska, extensively tested H. alpinum and found no traces of swainsonine or any other alkaloid in any part of the plant (Lamothe, 2007). Chris was not exhibiting the widely-known classic symptoms of swainsonine poisoning, which appear before weight loss: uncoordination, hypersensitivity, depression, blank-staring eyes, loss of awareness, and similar neurological symptoms (Harries et al., 1972). When you read Chris’s journal and see the photos he took of himself, it seems obvious that he was not suffering from swainsonine poisoning. Which makes perfect sense, since he wasn’t consuming any swainsonine.

The Moldy Seed Hypothesis

In September 2007, Matthew Power wrote an exposé, “The Cult of Chris McCandless,” in Men’s Journal, in which he made the point that Krakauer’s explanation of Chris’ death in Into The Wild was effectively refuted, since chemists had tested these seeds for toxins and found none. Power’s article received significant media attention, and at about this time, a new printing of Into The Wild hit the bookstore shelves across the country—in which Krakauer presents yet a third explanation for McCandless’s death—which, of course, still blames it on eating a wild plant.

This third, the “moldy seed” hypothesis, states that, although the seeds of H. alpinum are not poisonous and do not contain swainsonine, they probably became infected with a certain mold, Rhizoctonia leguminicola, which can produce swainsonine. If you ignore the fact that Rhizoctonia leguminicola is not known to infect H. alpinum, and the fact that Chris’s symptoms appear incompatible with Rhizoctonia poisoning (a hyper-salivating condition known as “slobbers”), you are still left with the problem that there is no evidence that Chris actually ate any moldy seeds—much less the “enormous quantities” that Krakauer proposes (and which would be required to cause poisoning). The only evidence that Krakauer gives to support this hypo-hypothesis is that McCandless collected some seeds during a rainy period and put some of them in a Ziploc bag. That’s it? Yup, that’s it.


Hypothesis Number 4

In the first printing of this book, I stated, “One begins to wonder if Krakauer will just continue to change his hypotheses ad infinitum as each one is logically and scientifically refuted.” He has exceeded my expectations.

In 2012 a fiction writer named Ronald Hamilton posted a paper about McCandless’ death online, in which he hypothesized that Chris died from lathyrism, a condition of irreversible paralysis that arises when malnourished people consume large quantities of a protein commonly abbreviated ODAP. This protein is found in a number of edible legumes, both wild and domestic, most notably the grasspea Lathyrus sativus.

Grasspea is regularly and harmlessly eaten by hundreds of millions of people, and is perfectly safe as part of a normal diet. However, it is a hardy and productive crop that sometimes yields well when staple grain crops are destroyed by weather extremes. In these situations, people may eat grasspea in unusually large proportions for an extended time period; coupled with severe malnutrition, this can result in lathyrism. This disease has occurred among the poorer classes in the Old World for thousands of years, and today is most common in parts of India.

Hamilton’s paper focused on a heinous grasspea feeding experiment conducted by the Nazis during WWII. After a brief and slanted overview of the grasspea and lathyrism, Hamilton presents test results purportedly showing the presence of ODAP in the seeds of Hedysarum alpinum (Hamilton, 2012). What Hamilton’s paper notably lacked was an analysis of Chris McCandless’s particular situation. Instead, Hamilton made his case that Chris died of lathyrism by repeatedly emphasizing the fact that the disease disproportionately affects young adult males—as if medical diagnoses are achieved through broad generalizations rather than specific observations.

Lathyrism is well known among foraging authorities; warnings regarding this condition are frequently found in the literature about a wild edible related to grasspea, the beach pea Lathyrus japonicus. However, a quick look at the basic facts of the case rules out this explanation:

     Chris’s symptoms and their progression were not compatible with lathyrism. The scientific and medical literature regarding lathyrism is in agreement that the onset of the disease requires a minimum of 2-3 months of continuously consuming grasspea as 30-50% of one’s diet, coupled with nutritional stress. Hamilton’s paper repeatedly mentions the association with starvation, and asserts that “the toxin takes five or six weeks to begin to exhibit its effect.” Our earliest evidence of McCandless eating the seeds of Hedysarum alpinum is on July 14 (which is about as early as they would have become available). Yet Hamilton claims that Chris was suffering severe effects of lathyrism only 17 days later. This is dramatically quicker than the disease is known to progress.

According to Hamilton, the paralysis caused by lathyrism is irreversible. Yet Chris was out collecting berries (apparently out of earshot from the bus) two or three weeks after his supposed paralysis; and he was able to walk to take a photo of himself shortly before his death. This, too, appears incompatible with lathyrism.

     There is no evidence that Chris consumed enough ODAP to cause lathyrism—and it seems incredibly unlikely that he could have done so. The seeds are small and light, snuggled in a comparatively large fruit called a loment. They are so laborious to hand-separate from the loments that it seems physically impossible to obtain them in a quantity sufficient to cause lathyrism.

Hamilton presented some weak evidence from  ill-designed  experiments (his “control” tests were on the vegetative parts of the grasspea plants rather than the seeds) suggesting that H. alpinum seeds contained ODAP. Krakauer subsequently had an analysis of the seeds done, which he claimed showed that they contained sufficient ODAP to cause lathyrism (more on this later).

However, the concentration of ODAP in the seeds is only one piece of the information needed to determine Chris’ dose of the toxin: we also need to establish what quantity of the seeds he ate. Despite Krakauer and Hamilton’s unsubstantiated claims that Chris ate “massive amounts” of Hedysarum seeds, we only know that Chris ate them two or three times over 17 days, and we don’t know in what quantity. Any claim beyond that is pure speculation. This dose is clearly insufficient to cause lathyrism.

Perhaps all of these arguments are moot in light of a basic understanding of lathyrism: this disease is not a cause of starvation—it is a symptom of it. If a rock climber falls 600 feet to his death, we don’t dwell on the possibility that he might have had a heart attack on the way down. It is irrelevant.

Despite the obvious shortcomings of Hamilton’s paper, Krakauer took Hamilton’s arguments and defiantly presented them to the media as thoroughly investigated, “brilliant” proof that McCandless had died from plant poisoning, both in an article published in The New Yorker (and in an interview with National Public Radio. In Krakauer’s words, this theory “appears to close the book on the cause of McCandless’s death.”

Almost every major media outlet in the English-speaking world parroted Krakauer’s statement without the slightest nod toward investigative journalism.

But wait. Chemists in Chemical & Enginerring News (Drahl, 2013) point out that the seed analysis that Krakauer had cited was being misinterpreted or misrepresented, and did not actually indicate the presence of ODAP as Krakauer had proclaimed. Ooops! Huge Surprise! Feb. 11, 2015, this directly from Krakauer’s update in The New Yorker: Hedysarum alpinum seeds apparently don’t contain any ODAP.


Theory 5

It didn’t take long for Krakauer to concoct a new theory for how plants can be blamed for starvation that occurred mostly before they were consumed. This time, he did it with the collaboration of four professionals, and their paper was published in the March 2015 issue (Vol 26, Issue 1) of Wilderness & Environmental Medecine. The periodical has made this article available for free, and I encourage interested readers to examine it. The investigators have found a different toxin, L-canavanine, in Hedysarum alpinum seeds. They present credible evidence that this toxin is actually present (must be a relief for Krakauer), and they conclude that it is “highly likely” that eating these seeds was a contributing factor in McCandless’s death.

Unfortunately, their paper reads more like a publicity stunt than a scientific investigation. Although their chemical analysis appears sound, the rest of the paper is problematic.

The authors claim that “there is evidence that H. alpinum seeds constituted a significant portion” of McCandless’s diet, and further state that his diary and photographs “indicate H alpinum seeds were a major component of his diet from July 14 to July 30.” This is a gross misrepresentation of the evidence. There are two statements written on a piece of paper: “Potato seeds” one day, and “Fault of pot seed” another day. And there is one photograph of a bag of H. alpinum loments. There is no more evidence than that. The contention that the seeds were a major component of Chris’s diet is speculation, and has no place in a medical journal.

The article shows a photo that McCandless took of a bag of H. alpinum loments and some other food items; the caption (mislabeling them “seeds”) states: “estimated dry weight 600 g.” There is no discussion of how this estimate was arrived at, as one would expect in a scientific paper—but it is an outrageous overguesstimate. Most of the volume of that bag would be discarded as the seeds were separated, and the dry weight of the seeds is no more than 250 g, and more likely only 30-80 g.

Although the authors repeatedly use the term “seeds,” as Krakauer has all along, it seems that they are really referring to the loments, as the caption suggests. This amateurish inaccuracy creates great uncertainty in interpreting their report. Having had both the seeds and the loments in my mouth, I will here assert that Chris probably ate the seeds, just as he reported in his journal, and not the much larger loments that contain them, which are worthless roughage of no value as food (and unpleasant in one’s mouth). It seems likely, then, that the authors did not actually analyze the part of the plant that Chris ate.

This paper also mentions a “precipitous decline” that led to Chris’s death after eating Hedysarum seeds. There is no evidence that this “precipitous decline” ever occurred; it is a fabrication of Krakauer’s. Indeed, a great body of evidence has been assembled demonstrating that McCandless underwent a steady decline commencing with his arrival in the Teklanika country. And it is worth noting, despite Krakauer’s assertion that eating something on July 30 debilitated Chris and caused him to starve, his journal makes it clear that he was hunting and gathering extensively for two weeks after that date. Chris wasn’t “laid low”—and he wrote a much more obvious cause for starvation in his journal a week after the alleged poisoning: “NO GAME.”

What is more remarkable is that the “Discussion” section of the paper mentions “the debilitation he experienced from the seeds” in a context implying that this event is fully established as having occurred. To use a hypothesis as one of the facts in building a case for itself is circular reasoning with no explanatory value. Its inclusion in such a discussion is an egregious failure of peer review.

It is puzzling how Krakauer and his collaborators can conclude that eating these seeds was likely a contributing factor in Chris’ death when they present no discussion of the quantity of H. alpinum seeds that Chris would have needed to ingest to produce symptoms. Could they really be ignorant of the basic relationship between toxicity and dose? Or perhaps they recognized that such an analysis would weaken, not strengthen, their case.

The concentration of L-canavanine the authors found in H. alpinum “seeds” was 1.2%. That’s substantially less than the concentration of this same chemical in alfalfa sprouts (Rosenthal and Nkomo, 2000). Malinow et al (1982) had to feed a species of monkey a diet of 40% alfalfa sprouts for 7 months to produce serious symptoms of canavanine poisoning. Based on this, Rosenthal and Nkomo conclude that “one could not reasonably eat sufficient alfalfa sprouts, even if one consumed nothing else” to produce such symptoms in a human. Moreover, the symptoms that Chris suffered from were only loosely similar to those expected for canavanine poisoning—and a perfect match for the symptoms of starvation.

Unlike lathyrism, the symptoms of L-canavanine poisoning subside after ingestion of the toxin is stopped (Malinow et al, 1982). Krakauer and his collaboratorss presume that McCandless stopped eating H. alpinum seeds after July 30. How, then, can they still attribute his starvation to eating these seeds? By the flimsy speculation that “the inadequacy of his diet precluded the possibility of recovery.” In other words, they argue that Hedysarum seeds caused him to starve because he was already starving when he ate them. At least they got that last part right.

In this WMJ article, there is no logic connecting the data to the conclusion supposedly supported by it.  The authors use the same defective reasoning that Krakauer has from the beginning: “If this is remotely plausible, it’s as good as true.” Krakauer’s latest threadbare hypothesis was not confirmed by the presence of a toxin—toxins can be isolated from most foods—nor was it strengthened by its publication in a peer reviewed journal. Conversely, the professionalism of the publication and its reviewers have been tainted by their association with an article that flouts the most basic precepts upon which science is based.

Rather than make a genuine effort to gather facts and draw sensible conclusions, Krakauer drew extravagant conclusions first; since then, facts have been conjured, contorted, or ignored to support them. His presentation of the matter seems stubbornly defiant, his reasoning perverse, and his arguments disingenuous.

With each successive hypothesis, Krakauer has diluted his credibility. Chris starved because e poisoned himself. No, because he couldn’t digest food. No, because he was paralyzed. No, because he was weakened. He ate the  wrong plant. No, he ate the wrong part. No, it just got moldy. Actually, it really was a little bit poisonous, and I bet he ate tons of it. It was swainsonine. I mean, ODAP. I mean, L-canavanine. He starved to death because he was starving, and when you’re starving, and you eat something that makes you starve, you starve all the way to death!

I am sure I will be completely convinced by hypothesis number six.

Krakauer ends his paper with a warning to foragers: that even if one part of a plant is edible; other parts may be toxic. Thanks buddy, for this public service message setting us all straight. True, this warning has been part of most reputable books ever written on the topic, but in order to take it seriously, we really needed to hear it from a botanical buffoon who is deeply invested in spreading unrealistic fears about our avocation.

Sean Penn’s Deliberate Deception About McCandless’s Death

In the movie version of Into The Wild, Sean Penn chose to portray McCandless poisoning himself according to Krakauer’s first hypothesis—mistaking wild sweet pea for wild potato. Although this had long ago been abandoned by Krakauer himself, the Poisonous Plant Fable seemed ideal for the big screen.This motif is integral to the film’s plot and development. It is introduced almost immediately, as Chris writes to Wayne Westerberg about his “new book on the local flora and fauna.” Soon after Chris arrives in the Arizona desert, there is a close-up of the cover of his copy of Outdoor Life’s Field Guide to North American Edible Wild Plants. In another early scene, Jan Burres, who he met on the road, says to him, “That book of yours is really cool and all, but you can’t depend entirely on leaves and berries.”

Later, after Chris is trapped by the high waters of the Teklanika River, the film shows him having an epiphany after reading the words “to call each thing by its right name” in Doctor Zhivago. After this, he takes the field guide Tanaina Plantlore and goes on a plant identification spree. Among the plants he identifies is Hedysarum alpinum. (In reality, Chris had already been collecting and eating this plant for several weeks by this time.) After eating this plant’s seeds, McCandless becomes very ill. Upon a second look at his book he realizes that he has mistakenly eaten H. mackenziei, the wild sweet pea. Further reading reveals that he is bound to die a slow, agonizing death, and he throws the book down in rage. Just before Chris expires, so that nobody forgets how he perished, the movie hauntingly repeats the words, “To call each thing by its right name. By its right name.”

The message is clear: Eating wild plants will kill you.

But it’s a lie.

Although it is understood that some details of a story will be changed to make it more friendly to the motion picture format, most viewers assume that a film “based on a true story” depicts things that at least remotely approximate the truth—especially when it comes to the most significant event in the entire story. The film’s most egregious deception occurs when Chris opens up Tanaina Plantlore (Kari, 1987). The book’s actual cover is shown, but when Chris flips to page 128 to read about H. mackenziei, the movie shows a counterfeit page that the producers have forged and inserted. The excerpt from the book that McCandless reads in the film goes like this (Yes, it really does go like this; the apparent errors and omissions are original.):


"The lateral veins, nearly invisible on leaflets of wild sweet pea the plants poisonous seedlings. If ingested symptoms include partial motor paralysis, inhibition of digestion, and nausea. If untreated leads to starvation and death. Another way to distinguish is that the stem of the wild sweet pea is mostly unbranched."


That’s strange, because when I open to page 128 in my copy, it only says this in the same place:


"The lateral veins of the leaflets of wild sweet pea are hidden, while those of the wild potato are conspicuous. Another way to distinguish between the two plants is that the stem of the wild sweet pea is mostly unbranched, while that of the wild potato is definitely branched."


In real life, the book has no mention whatsoever of “partial motor paralysis, inhibition of digestion, and nausea,” nor of “starvation and death.” The movie paused on a fragment of text representing each of the primary components of the Poison Plant Fable: “poisonous,” “and death,” and “the plants resemble each other.” The focus on “lateral veins” corresponds to the “even experts” component of the fable, as does the subtly changed wording from “hidden” to “nearly invisible.”

If this movie was made “in memory of Christopher Johnson McCandless,” as it claims, then why was a fraudulent, insulting scene fabricated for his death? Chris’s life story has been usurped by the very same propaganda machine that he so vehemently rejected, twisted into a fable for the purpose of casting fear and doubt into those who would seek what he sought. The greatest lessons that could be learned from his life are now buried under lies.

So how did Chris McCandless die?

He starved to death. His autopsy confirmed this. When Chris’s body was found, it weighed 67 pounds; it was estimated that his weight at death was 83 pounds, with a body mass index of 13.3 (Lamothe, 2007). Death from starvation usually occurs when body mass index falls to about 13 (Shils et al., 1994; Henry, 1990). The proportion of weight that Chris lost was comparable to that normally associated with victims of concentration camps, severe famine, anorexia nervosa, and death by starvation (Keys et al., 1950). Even Chris’s own journal, nineteen days before his death, says, “Starving. Great Jeopardy.”

Keys et al. (1950), in their famous and fascinating study of human starvation, point out that starving people become exceedingly preoccupied with food, writing and talking of little else. Krakauer and others were struck by this very feature of Chris’s journal throughout his entire stay in the Alaska bush. The journal entries clearly show that he was not getting nearly enough calories. He took a photo of himself after killing a porcupine in which he appears dangerously malnourished—the last porcupine he ate was 52 days before ingesting the seeds that Krakauer claims starved him. The medical examiners who performed Chris’s autopsy noted telltale signs of starvation: severe deterioration of his muscles and a lack of subcutaneous fat. This can’t happen suddenly.

The only reasonable conclusion is that Chris died of regular starvation.

Then why does Jon Krakauer insist that Chris McCandless died from eating a wild plant?

When the story of Chris McCandless’ death hit the media, it produced a strong negative reaction among some people, particularly many Alaskans. McCandless was publicly ridiculed and lambasted, and Krakauer wanted to provide a counterpoint.

I don’t disagree with him. Although Chris made serious and egregious mistakes, this is not a sensible reason to become furious at him or about what he did. The impulsive disparagement levied toward Chris displays the insecurities of a kind of redneck found in every rural district—one who feels deeply threatened by those who do things that he would not dream of trying and can’t understand. Only on the surface is this criticism about his fatal mistakes. Chris’s death verifies his critics’ self-image as rugged frontierspeople, and renders him a defenseless target.

Shortly after the story broke, the Alaskan hunters who found McCandless’s body ridiculed him, saying that he had killed a caribou and mistaken it for a moose. In the words of Gordon Samel, “When I read in the paper that he’d thought he’d shot a moose, that told me right there he wasn’t no Alaskan. There’s a big difference between a moose and a caribou. A real big difference. You’d have to be pretty stupid not to be able to tell them apart,” (p. 177). But there is no doubt that Chris did, in fact, kill a moose; his photos clearly show it. These Alaskans not only couldn’t identify the animal’s remains, but they derided Chris for getting it right.

This is a microcosm for much of the criticism Chris has received. When people suggest that “Alaskans do that kind of stuff all the time,” they are kidding themselves. What they actually mean is that Alaskans go into the bush with vehicles, lots of gear, and ample food supplies; why couldn’t Chris just do the same? This is as irrelevant as mocking a marathon runner because you can get to the finish line faster in your car. There is nothing inherently moronic about what Chris tried to do; he just failed.

I understand Krakauer’s desire to defend McCandless from such crude and childish attacks. Having Chris die from a poisonous plant that could even fool “experts” makes him seem less foolish and overconfident than if he died by simple starvation. But Krakauer has carried this defense too far. His assessment of Chris’s health during his stay in the bush is nonsensical. Krakauer claims that Chris “feasted regularly” on “a bounty of wild meat,” an “apparent munificence,” and claims that “the country was a fecund riot of plant and animal life, and his food supply was adequate” (p. 188). Krakauer also shares that “game seems to have been plentiful” and that Chris was “fending for himself quite nicely in the country” (p. 171). Yet an examination of Chris’s journal shows that he went without food on many days and almost always had an extreme caloric deficit; he wrote of “famine” on May 9!

When Chris tried to leave the wilderness in early July, he probably did so because he realized that starvation was an imminent threat. He took a picture of himself at that time, about which Krakauer says, “He looks healthy but alarmingly gaunt. Already his cheeks are sunken. The tendons in his neck stand out like taut cables” (p. 169). Krakauer later adds this bizarre assessment: “His meager diet had pared his body down to a feral scrawn of gristle and bone, but he seemed to be in reasonably good health” (pp 189). Healthy, except for being gravely malnourished and on a trajectory toward death.

Krakauer keeps citing the journal entry: “Extremely weak. Fault of pot seed. Much trouble just to stand up. Starving. Great Jeopardy” as if a healthy person who suddenly feels weak will starve to death three weeks later. On the one hand, he assumes that Chris has made an infallible and all-encompassing medical self-diagnosis regarding potato seeds; simultaneously, he discounts Chris’ well-supported and equally clear self-diagnosis of great jeapordy from starvation. Krakauer’s argument that before July 30, there was “nothing to suggest that McCandless was in dire circumstances” obstinately ignores three months of drastic food shortage before this date.

Lamothe (2007) modeled Chris’s food intake versus requirement, based on World Health Organization gudelines, and showed that his caloric deficit alone was sufficient to cause death. This supports the conclusion that Chris McCandless died of starvation—just like the medical examiner concluded. This also explains the “mystery” of why Chris didn’t do more to save himself: the advanced stages of starvation are characterized by an extreme listlessness, weakness, and depression (Keys et al., 1950), all of which were probably aggravated by low-level lead toxicity from the game he was eating (ND Dept. of Health, 2008).

I can sympathize with Krakauer’s desire to portray McCandless in a positive light, but there comes a time when you must let go of an extravagant pet theory.

What lessons about wilderness survival and wild food can be drawn from the story of Chris McCandless?

Whatever you think of Chris as a person, it is hard to deny that he overestimated his skills and underestimated how much knowledge—and food—he would need. Despite some vocal anti-McCandless opinions, he was not ill-equipped or under-equipped; he was unskilled and unprepared. He didn’t need a better map or a high-powered rifle. There are many knowledgeable and skillful people who have returned from similar adventures in good health, and who would have thrived with the same gear and in the same circumstances under which he starved to death.

In a short-term survival situation, food is of minor importance. However, in long-term survival or “living off the land,” it is of paramount importance.

Chris grossly underestimated the amount of food that he needed. Before his trip to Alaska he had spent periods on a negative calorie budget and lost a great deal of weight. At one point his journal (oddly written in third person) said, “Malnutrition and the road have taken their toll on his body. Over 25 pounds lost” (p. 37). Yet he was always able to access food after these excursions and restore his body mass. During such a replenishment period, after a time of living on wild plants, Jan Burres described him as “big-time hungry. Hungry, hungry, hungry” (p. 30). It is OK to lose twenty pounds over three weeks, but continuing that same negative calorie budget over several months is deadly.

We get food so easily and automatically that we hardly consider the quantities that we require, or its calorie content. What Chris did is common for wilderness survivalists today, who typically “survive” on negative calorie budgets, steadily losing weight. The only difference is that their excursions are normally of less than a month’s duration, and they simply gain back the lost weight after returning to civilization. (An excellent description of this process of survivalist starvation followed by binge eating can be found in The Last American Man [Gilbert, 2002], pp. 52–63.) I believe that this is exactly what Chris intended to do, just as he had done before; but his attempt to leave was thwarted by a collusion of unforeseen conditions, weakness, and injury.

Maintaining one’s weight and health over the long term is an entirely different proposition. It doesn’t help that many survival books and instructors teach that only very small amounts of food are needed in the bush. McCandless’s experience should serve as a lesson to any survivalist who entertains these caloric delusions. Making believe that Chris died by poisoning robs us of this important and potentially life-saving lesson, and instead imbues us with an unrealistic and unfounded fear that only makes us more likely to perish in the wilderness.

I like to measure my food in calorie-days—the number of days of my full caloric requirement that the food represents. I calculated Chris’s calorie requirement as 3,300 per day based on his age, gender, a body weight of 145 pounds, and heavy physical activity, using guidelines from Grodner et al. (1996). This estimate is rough, and the true figure would depend on many unknowable variables. Still, my point is easily demonstrated: McCandless didn’t have nearly enough food. He began his journey on April 28 with a ten pound bag of rice—which constituted less than five calorie-days. By May 9, he had only killed one grouse and had written “4th day famine” in his journal. The rice was already long gone.

When Krakauer insists that McCandless had sufficient food in the Alaska bush, it makes me suspect that he has never lived on red squirrels. I eat three in one meal, and that’s with wild rice and vegetables.

The squirrels that McCandless was eating (Tamiasciurus hudsonicus) typically weigh five to nine ounces (Whitaker, 1996). Using seven ounces as an average, and realizing that after subtracting the skin, tail, head, bones, feet, and entrails, the edible flesh would constitute about 40 percent of that weight, or 2.8 ounces of meat per squirrel. This means that he would have needed to eat about twenty-five squirrels per day to meet his caloric requirement. If he carefully removed and ate the liver, kidneys, kidney fat, heart, lungs, and brain of each squirrel, he would have about doubled the calories that he received from each animal. Since he probably did this to some extent, I estimate that he needed roughly sixteen squirrels to equal a calorie-day.

I can find no estimate of the caloric value of H. alpinum roots. I use figures for parsnips in these calculations, since they seem like the most physically similar cultivated vegetable. (Note that, despite the common name “wild potato,” H. alpinum is not closely related to potatoes, nor similar in form.) If parsnips have similar energy content, Chris would have needed about nine pounds of wild potato roots to equal one calorie-day.

Since we don’t know exactly which berries Chris was eating and in which proportions, I calculated with the caloric value of blueberries (which is actually higher than that of some of the berries he was eating). It would have taken about thirteen pounds of blueberries to equal one of Chris’s calorie-days.

A hypothetical day’s food for Chris might consist of half squirrel meat, and a quarter each of berries and wild potato roots. In this case he would have needed eight squirrels, 2 ¼ pounds of roots, and 3 ¼ pounds of berries each day. I don’t propose that he ever ate exactly this complement of food—that detail is insignificant. What matters is that his food journal clearly shows him getting only a small fraction of the calories he needed. (Note: the calorie content of various foods used in this section are derived from Grodner et al., 1996, except for dry rice, which is from Van Wyk, 2005.)

If this seems like a high volume of food, that’s because it is. We have sought, developed, cultivated, and become accustomed to calorie-dense foods for so long that most of us have never been without them. We’ve never had to eat food in volumes like this. When you realize that a stick of butter has as many calories as two and a half quarts of blueberries or seven pounds of broccoli, you can see why the innate human desire for calorie-rich, low-fiber food developed.

You can’t just eat whatever is edible; you must eat food in appropriate proportions.

This is a big shocker to modern folks, who get to pick and choose their dietary proportions from an almost endless variety of easily acquired food. Most of us have never really faced this challenge. The survivalist often imagines that she can find an edible plant and just eat it until she is full, but this is simply not so.

Chris had access to a lot of lingonberries. If he didn’t get any meat, couldn’t he just eat more lingonberries and get all his calories that way? Absolutely not. He would have needed to eat almost three gallons of lingonberries per day. He’d probably be vomiting before finishing the second quart. No matter how many lingonberries were available to him, his body would have only accepted them for a small portion of his caloric requirement. This doesn’t make lingonberries “poisonous”; the same is true of virtually every food, although the appropriate proportions vary. Toxicologists do not consider an illness from overindulgence to be a poisoning (Kingsbury, 1965).

The concept that foods can be eaten only in appropriate quantities is taken so much for granted that, to my knowledge, it has never been given a name in the medical literature. I call it the maximum caloric proportion (MCP). Some foods have a very high MCP, such as milk, meat, and potatoes. They are easily digested and contain few antinutrients or toxins, thus they are suitable as dietary staples. Others, such as cabbage, rhubarb, and raspberries, cannot serve as staple foods and are only suitable to supply small portions of the diet. As one travels north, there tends to be fewer plants with a high MCP; this is why hunter-gatherers from northern latitudes ate meat for the great majority of their calories.

Don’t underestimate the skills and knowledge that living off the land requires.

Chris was neither a good hunter nor a good gatherer. He either didn’t realize these facts, or didn’t think they mattered. Identification represents perhaps one percent of a seasoned gatherer’s knowledge about a particular plant. The rest is learned from experience, not books. Each plant is a complex skill, which often takes much time to master. An experienced harvester might locate a plant in half the time of a novice and select better specimens, harvest them six times as fast, then process and prepare them in only a quarter of the time. Even with a skill as deceptively simple as berry picking, skilled collectors typically acquire two to four times as much as inexperienced pickers beside them. Such disparities add up enormously and can be the difference between life and death in a survival situation.

McCandless was also a complete novice when it came to hunting. Skilled hunters kill many times more game than the inexperienced. Porcupines, red squirrels, and spruce grouse are notoriously easy to kill. Of course, he should have eaten easy prey, but mention of the more elusive game is mostly lacking. Snowshoe hares, for example, are found in the same area and provide about six times the meat of a squirrel, but they also require more skill to hunt. It takes years to become a proficient hunter, and Chris sorely lacked such experience. This callowness is all the more egregious when you consider that Chris was attempting to survive in a landscape where high-calorie plant foods do not exist, and hunter-gatherers subsisted largely on meat.

In a very real sense, Chris was killed by the ignorance he displayed when he killed the moose. It took him two days to finish removing the internal organs, which should have been done within an hour or two. He didn’t even commence with smoking the meat until four days after the kill. In June! Beyond this, it is honestly quite hard for me to imagine the naivety that would be required to not know that meat should be preserved by cutting it into thin strips and drying. Sure, plenty of people don’t know this—but they aren’t going into the wilderness alone without provisions. Chris was attempting to live off the land. If he had time to read Tolstoy, why didn’t he have time to read about what he was doing? There is an abundance of literature on this topic, and he could have easily done a little research and discovered that this was the standard way to store meat before freezers, almost everywhere in the world. Even a small moose would have provided at least sixty calorie-days, virtually ensuring his survival if he had only known a few basic facts.

Everything he needed was amply supplied, except for knowledge and resourcefulness. He just failed to take advantage of it.

If you are going to live off the land, food needs to be a priority, not an afterthought.

In a long-term subsistence situation, food is the priority. In former times, the native people of the Far North planned each move according to food availability. McCandless largely ignored this consideration, planning his entire wilderness experience based on aesthetic and philosophical considerations.

Moreover, the entire trip was ill-conceived from this standpoint. If Chris was really planning on feeding himself from the wild, he should have gone to a place with a lot of wild food. Instead, he chose what is arguably one of the most difficult places in the country to feed oneself. This is a mistake that I often encounter. People want to go to a remote, wild area to live off the land. Ironically, these areas are remote and wild precisely because of their limited biological production (i.e., hardly any food).

Chris did not seem to think food mattered very much. One wonders how much this had to do with the influence of Tolstoy and Thoreau. Shortly after his terrible experience wasting the moose, he highlighted his passage from Walden:


I believe that every man who has ever been earnest to preserve his higher or poetic faculties in the best condition has been particularly inclined to abstain from animal food, and from much food of any kind.


This was not a vacation to Chris; it was a vision quest. I believe that, in the early part of his stay, he saw his caloric deprivation as some kind spiritual necessity and moral statement. By the time he changed his mind, it was too late, and his inexperience caught up with him.

Survival or “Earth living” entails more work than many people claim.

There is a prevalent myth that living by hunting and gathering requires only “two hours of work per day.” Many authors and teachers of wilderness survival preach this, but it is groundless. The idea is based on the work of a few anthropologists (Richard Lee, Irvin DeVore, James Woodburn, and McCarthy and McArthur), popularized by Marshall Sahlins (1972). If you take the findings of these anthropologists out of context, they may seem to support this claim, but careful reading of the original studies brings to light a few things worth pointing out. First, two hours per day was the lowest estimate made in any of these studies. Second, the subjects were life-long professional hunter-gatherers who had been familiar with their respective areas all their lives. Third, most of these estimates did not include the time required for food preparation and other tasks such as building shelters or crafting tools. Further, the estimates are for groups of people, and so represent the many advantages that collaboration and division of labor provide. And finally, the observations come from tropical cultures which invested little to no labor in shelter, clothing, long-term food storage, or containers. Two hours of work per day might feed you—if all of these conditions apply to your “survival” situation.

Many survivalists have been confused and rattled by this myth, thinking that things are so hard for them either because they are inept, or because they just can’t find the hamburger tree. Today we are fed with such ease that, when thrust into a subsistence or survival situation, most people find it remarkably difficult to muster the diligence and effort necessary to acquire sufficient calories. When this frustration is compounded by inexperience, some people are shocked into near paralysis. I suspect that, at least to some degree, this happened to Chris McCandless.


In this essay, I do not wish to pass any judgment on Chris McCandless. He made incredible mistakes, overestimated himself, and underestimated “The Wild,” but that does not make me scornful of him. In fact, I admire his courage despite his fatal hubris. I also admire his search for truth and meaning in a world that is often shallow and materialistic. The fact that he died in this search in no way diminishes the lasting truth of the answers he found. To that end, I hope he would appreciate what I have written here.


Drahl, Carmen. 2013. “Chemists Dispute How ‘Into The Wild’ Protagonist Chris McCandless died.” Chemical & Engineering News Vol 91, Issue 43, 30-31.

Krakauer, Jon, Yin Long, Andrew Kolbert, Shri Thanedar, Jonathan Southard. “Presence of L-Canavanine in Hedysarum alpinum Seeds and Its Potential Role in the Death of Chris McCandless.” Wilderness & Environmental Medecine Vol 26 Issue 1, 36-42

Malinow, MR, EJ Bardana, and P. McLaughlin. 1982. “Systemic lupus erythmatosus-like syndrome in monkeys fed alfalfa sprouts: role of a nonprotein amino acid.” Science 216: 415-417.

Rosenthal, Gerald A. and Palesa Nkomo. 2000. “The Natural Abundance of L-Canavanine, An Active Anticancer Agent, in Alfalfa, Medicago sativa (L.)” Pharmaceutical Biology 38(1): 1-6.