The tragic story of Christopher McCandless, chronicled in Jon Krakauer's book Into the Wild, has fascinated readers for decades. While the official cause of death was ruled starvation, a significant debate has centered on the role of a potentially poisonous plant in his final days. Years of evolving theories and scientific investigation ultimately pinpointed the seeds of the wild potato plant, Hedysarum alpinum, as the culprits behind his debilitating weakness.
The Wild Potato Theory: From Speculation to Scientific Proof
Following the discovery of McCandless’s emaciated body in 1992, the initial coroner’s report concluded death by starvation. However, a cryptic diary entry McCandless left behind hinted at another cause, stating, "EXTREMELY WEAK. FAULT OF POT[ATO] SEED. MUCH TROUBLE JUST TO STAND UP. STARVING. GREAT JEOPARDY.". This note led Krakauer to investigate the wild potato plant, a food source McCandless had been documented as eating.
The Shifting Hypothesis
Initially, Krakauer theorized that McCandless might have mistaken the edible wild potato for the poisonous wild sweet pea, a similar-looking plant. This was later dismissed, as McCandless had used a field guide that clearly differentiated between the two species. Subsequent tests on the wild potato seeds found no toxic alkaloids, leading to more dead ends.
Other theories, such as toxic mold or the neurotoxin ODAP, were also investigated and ultimately disproven by further analysis.
The Discovery of L-canavanine
The definitive answer was discovered when Krakauer and a team of chemists identified a toxic amino acid called L-canavanine in the wild potato seeds. L-canavanine is an antimetabolite that interferes with metabolic processes and is toxic to animals. Research indicated that L-canavanine poisoning is particularly dangerous for individuals who are under stress, malnourished, and engaging in heavy physical activity, matching McCandless’s condition. The toxin would have caused a gradual weakening, leading to paralysis-like symptoms and preventing him from foraging.
How McCandless’s Diet Led to His Death
McCandless consumed the roots of the wild potato, which are edible, but later ate a large quantity of the seeds. These seeds contained L-canavanine, a potent toxin not present in the roots. The combination of a poor diet, physical exertion, and the toxin's effects led to his rapid decline and inability to survive.
Plant Parts and Their Effects: A Comparison
| Plant Part | Edibility Status | Potential for Toxicity | Effect on McCandless |
|---|---|---|---|
| Wild Potato (H. alpinum) Roots | Edible | None documented | Provided some calories, but not enough to sustain him |
| Wild Potato (H. alpinum) Seeds | Toxic | Contains L-canavanine | Caused extreme weakness and paralysis, preventing further foraging |
| Wild Sweet Pea (H. mackenzii) | Poisonous | Often mistaken for wild potato | Not consumed by McCandless, despite initial speculation |
Conclusion
The answer to what did Chris McCandless eat that was poisonous is found in the overlooked toxicity of the wild potato seeds, specifically the presence of L-canavanine. His death was a tragic result of an unknown danger within a seemingly safe food source, which incapacitated him and led to his demise. The scientific investigation highlights the complexities of wilderness survival.
The Unresolved Debates
Despite the strong scientific evidence presented by Jon Krakauer and his team, some debates persist regarding the precise contribution of the wild potato seeds versus overall malnutrition and McCandless's decisions. However, the discovery of L-canavanine provided a crucial piece of the puzzle.
For more in-depth information on the scientific research, see Jon Krakauer's article "How Chris McCandless Died: An Update" on The New Yorker website.
