Presence of L-canavanine in Hedysarum alpinum seeds and its potential role in the death of Chris McCandless.

OBJECTIVE For the past 2 decades there has been vigorous disagreement over the purported toxicity of Hedysarum alpinum seeds, and whether the consumption of such seeds was a factor in the 1992 death of Chris McCandless, the subject of the book Into the Wild. Our objective was to confirm or disprove the presence of L-canavanine (a nonprotein amino acid known to induce systemic lupuslike symptoms in humans) in H alpinum seeds. METHODS Liquid chromatography-tandem mass spectrometry analysis of H alpinum seeds was performed. RESULTS Our analysis confirmed the presence of L-canavanine in H alpinum seeds and demonstrated that it is a significant component of the seeds, with a concentration of 1.2% (weight/weight), roughly half of that found in Canavalia ensiformis. CONCLUSIONS The data led us to conclude it is highly likely that the consumption of H alpinum seeds contributed to the death of Chris McCandless.