His statement brought to mind the movie "Into the Wild" - which I heard of somewhere on a TV review - about a young man that goes into Alaska to survive on nature and though he eats plentiful nuts and seeds, roots etc., succubms to what they think may be food bourne or derived illness.
"As Krakauer explains, McCandless had been eating the roots of Hedysarum alpinum, a historically edible plant commonly known as wild potato (also "Eskimo potato"), which are sweet and nourishing in the spring but later become too tough to eat. When this happened, McCandless may have attempted to eat the seeds instead. Krakauer theorizes that the seeds contained a poisonous alkaloid, possibly swainsonine (the toxic chemical in locoweed) or something similar. In addition to neurological symptoms such as weakness and loss of coordination, the poison causes starvation by blocking nutrient metabolism in the body.
According to Krakauer, a well-nourished person might consume the seeds and survive because the body can use its stores of glucose and amino acids to rid itself of the poison. Since McCandless lived on a diet of rice, lean meat, and wild plants and had less than 10% body fat when he died, Krakauer theorized he was likely unable to fend off the toxins. Roots of wild potato were used extensively by Aboriginal people, eaten both raw and cooked and used as a licorice substitute. Inuit hunters eat wild potato roots while hunting. However, when the Eskimo potatoes from the area around the bus were later tested in a laboratory of the University of Alaska Fairbanks by Dr. Thomas Clausen, toxins were not found, because there was no fungus on the seeds during this test, which contains the poisonous alkaloid.
In the most recent edition of his book, Krakauer has slightly modified his theory regarding the cause of McCandless' death. He believes the seeds of the wild potato had been moldy, and it is the mold that contributed to the seeds' toxicity. "