The Real Reason Into the Wild’s Chris McCandless Died

As with Aron Ralston, the story of Chris McCandless has sharply divided observers, between those who see him as a


As with Aron Ralston, the story of Chris McCandless has sharply divided observers, between those who see him as a hero for eschewing a materialistic, traditional western life and those who think he was an idiot who got in over his head and then paid the ultimate price in the Alaskan bush. There’s also been disagreement over precisely what caused McCandless’s death, but new evidence assembled by curious writer and then chronicled by Into the Wild author Jon Krakauer points a likely final verdict: poisoning from a toxin unknown to be in the wild potato seeds he consumed, which led to McCandless’s weakening, paralysis, and starvation.

In a piece in the New Yorker, Krakauer spins a detective tale of chemistry and curiosity. McCandless foraged and ate wild potato seeds in his last months spent just north of Denali National Park, which contained no known toxins or harmful substances but that he suspected were killing him. “EXTREMELY WEAK. FAULT OF POT[ATO] SEED. MUCH TROUBLE JUST TO STAND UP. STARVING. GREAT JEOPARDY,” he wrote on July 30, a few weeks before he died.

Krakauer’s first writing on McCandless, an article in Outside, speculated that the wilderness pilgrim had mistaken the seeds of wild potato, hedysarum alpinum, with the seeds of wild sweet pea, hedysarum mackenzii, a plant thought to be toxic and that was strikingly similar to hedysarum alpinum. By the time he’d spun the article into the book, Krakauer changed his mind. McCandless would not have mistaken the two plants, he thought, and Krakauer now speculated that wild potato seeds contained an alkaloid called swainsonine. Tests by a top chemist, Dr. Thomas Clausen, turned up nothing problematic. “I tore that plant apart,” Clausen said. “There were no toxins. No alkaloids. I’d eat it myself.”

It’s been 21 years since McCandless died, and people remained interested in him, including Ronald Hamilton, an author and employee at Indiana University of Pennsylvania, who stumbled upon Into the Wild and immediately suspected he knew how McCandless died.

Hamilton had read a book about a World War II concentration camp in Ukraine called Vapniarca, where Jewish inmates were fed bread made with flour from pea grass, lathyrus satius, which has been known for at least 2,000 years to lead to weakening and paralysis in the legs, especially in young men. The effect is even named after the plant and is called neurolathyrism, or lathryism. Pea grass, it turns out, contains a neurotoxin called beta-N-oxalyl-L-alpha-beta-diaminoproprionic acid, or ODAP for short.

Hamilton posted a paper to a Chris McCandless website speculating that wild potato also contains ODAP and that the reason previous efforts to find a toxin in the plant failed because chemists were looking for alkaloid-based poisons, not proteins like ODAP. He had contacted Clausen’s chemistry team, who agreed they might have missed a protein-based toxin, and the convinced the chemistry department at Indiana University, to test his theory with seeds and roots of both hedysarum alpinum and hedysarum mackeniei, plus lathyrus satius and pure ODAP. The results were a smoking gun.

“The seeds of both of the hedysarum plants showed even higher concentrations of the deadly protein toxin ODAP than was contained in the tissues and fibers of the lathyrus sativus plant itself,” wrote Hamilton. “Only purified ODAP showed a higher concentration of the toxin.

“It might be said that Christopher McCandless did indeed starve to death in the Alaskan wild, but this only because he’d been poisoned, and the poison had rendered him too weak to move about, to hunt or forage, and, toward the end, “extremely weak,” “too weak to walk out,” and, having “much trouble just to stand up.” He wasn’t truly starving in the most technical sense of that condition. He’d simply become slowly paralyzed. And it wasn’t arrogance that had killed him, it was ignorance. Also, it was ignorance which must be forgiven, for the facts underlying his death were to remain unrecognized to all, scientists and lay people alike, literally for decades.”

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Steve Casimiro is the editor of Adventure Journal.
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Showing 31 comments
  • Charles Kelso
    Charles Kelso

    Damn. Double whammy!

  • Ian

    GREAT article. RIP Alexander Supertramp.

  • Kelly Blake
    Kelly Blake

    The New Yorker piece was so interesting. Thanks!

  • Kamini Fonseca
    Kamini Fonseca

    So awesome to know a truth sometimes no matter how horrrible it may be…as it will no doubt lead to less nontruth! This made my day in a very special way…thanks for sharing!

  • JC
  • Will Snider
    Will Snider

    Sean Sean Stockman

  • Bryan Flores
    Bryan Flores

    On one hand the guy is a hero to me, on the other he was a complete ignorant fool, dead because of his arrogance towards most things modern. I too shook of the chains of everyday life, traveled Southeast Asia and then spent three years living in the bush of Alaska, not a few miles off the road like Chris, but to places accessible only by a two hour bush plane flight. I survived as many did before me by doing some research before going. My mantra “What one man can do, so can another” played through my head everyday, but I was not arrogant, I learned from previous generations, I read books, I understood basic biology and weather patterns. Chris’ story is one of misguided hope, but I think it is safe to say also that Chris was entirely foolish. Alaska has killed stronger men than most. If the potato seeds didn’t kill him, something else would have. Nobody goes into the bush (he wasn’t really in the bush, since he was only a few miles off the road system) without being prepared and that was his downfall. He had no real Northern outdoor experience, hell he went into the woods with only a .22 and a sack of rice. Most would say that is a suicide mission. Who knows, maybe it was.

    • kreg

      cool story bro

  • Sumy Guzman
    Sumy Guzman

    The toxin was in the bacteria in the seed. Not toxin “in the seed”. This death has already been studied

  • Sammy Mcgehee
    Sammy Mcgehee


  • Mina Cheriki
    Mina Cheriki

    Mackenzie Sheehan

  • Andrew Pick
    Andrew Pick

    If anyone read the book and the ending specifically you should know he ate the wrong berry, and it the toxins sucked any life he had out of him

  • Danau Taman Hidup
    Danau Taman Hidup

    True story

  • Ken Peterson
    Ken Peterson

    Indiana University of Pennsylvania representing!

  • Doug Robinson
    Doug Robinson

    I just read Krakauer’s New Yorker piece too. Great!

  • Jay Long

    Great story. Gotta respect a guy that wants to get away from it all that bad, and actually follows through on a plan. Whether he was ill-prepared or not, he wanted to walk away and he did. God bless him and may he R.I.P. Great piece.

  • Steve Casimiro
    Steve Casimiro

    Yeah, it’s great, but the real credit goes to Ronald Hamilton. A lot of the backcountry for JK’s piece comes from him and his report is even more fascinating that Krakauer’s.

  • Irideus Steelhead Fly Fishing Products

    A close buddy drove by the road yesterday. He was only 5 miles from the road.

  • Dawn Kirk
    Dawn Kirk

    He DID NOT DIE FROM EATING THE WRONG PLANT! He simply didn’t have enough provisions & starved to death…DUH. There were no toxic plants nor bacteria..Double duh.

  • Doug Robinson
    Doug Robinson

    Yes, I was certainly impressed with Hamilton’s words quoted by Krakauer. He obviously did the groundbreaking work there.

  • Selina

    This is my boyfriend’s favorite movie–it was kind of hard-hitting for me though. I really admire Chris’ willingness to surrender himself to nature’s will.

  • GOOG

    After reading the book and the articles all I felt was sadness for his family. A highly educated young man died because he got in over his head. The moral of this story has nothing to do with his bravery or wanderlust or inspiration. He was dumb and died. I still listen to Eddie Vedder’s soundtrack weekly so something good did come out of this.

  • The Outdoor Times
    The Outdoor Times

    Fascinating story. And still inspiring debate two decades on.

  • E12 Photography
    E12 Photography

    Who didn’t cry at the end? come on own up :-)

  • Tobin

    Interesting to see the commentary still being generated and potential toxins causing paralysis. What I also find interesting is the discussion about ignorance and getting in over his head. Can we say that about many others who have also died while out pushing boundaries. Having had a number of friends die on mountains and rivers – who were not ignorant, but may have been getting in over their heads – as part of pushing boundaries – how do you separate out them from Chris McCandless? In my current profession as a firefighter, I often see successes that are mere inches and seconds away from tragedies – as is often seen in other cases. In my mind at least, not quite so easy to separate.

    • Sungirl111

      I totally agree Tobin, and well put! It’s always amazed me how this story seems to generate such malice and anger. When I backpacked for two (non-consecutive) years many moons ago, I cringe now at some of the rookie mistakes I made, even as I had stocked up on guidebooks, etc. Chris McCandless was barely more than a child, full of dreams and wanderlust, and an incredibly insightful and couragous individual. I think it’s the latter that may twig some people the most, as it hi-lights their inability to take those kinds of risks in the name of adventure and curiosity. There is even a slight bias in this interesting article about ‘forgiveness’ for his ignorance (!?) We’d be hard-pressed not to find any one amoung us who have not made mistakes or taken a wrong step or turn. No forgiveness is necessary, but it’d be great to see less judgment. I can’t help but sense quite a margin of envy in those who criticize this boy’s quest for meaning.

  • Kathleen Rock

    I loved the book and the story. This is one of my favorite topics. The guy did a great thing in rejecting things that are legitimate problems such as a society obsessed with safety and comfort. In my opinion he was reacting to false relationships , materialism and utilitarianism but he didn’t have to leave the wake of destruction he caused to do so. Too bad he died and didn’t realize the value of other people and relationships until it was too late.
    The adventure part is totally awesome and I admire it. When I was wandering the earth it was hard on my family and friends and I still kept in touch and maintained a relationship with them. Would have been selfish not to.

  • Richard

    Chemist are not yet convinced that the science in the New Yorker is correct. Work is still on going…

  • Finding Into the Wild's Magic Bus

    He had to be ill. Otherwise you swim for it. Who starves to death looking across a river? Not this guy.

  • Bob FRost

    I just saw the movie last night for the first time, not knowing how it would end but when I saw the bus, I remembered back several years about a hiker that was found deceased. Rest in peace, you were living life as you wanted and had wonderful guidance along the way.

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