It all started back in the 1960s, when ape-watching anthropologists, Drs. Jane Goodall and Richard Wrangham, observed chimps foraging for a specific variety of leaf, which they consumed whole while wrinkling their noses in presumed disgust. Subsequent study showed that the leaves contained a powerful anti-parasitic compound.
A similar observation followed in 1987 by Dr. Michael Huffman from the University of Kyoto. During his year of living in the jungles of Tanzania, he observed chimpanzees in their native habitat. On one unexpected morning, he observed a female chimp, Chausiku:
“ Chausiku goes directly to and sits down in front of a shrub and pulls down several new growth branches about the diameter of my little finger. She places them all on her lap and removes the bark and leaves of the first branch to expose the succulent inner pith. She then bites off small portions and chews on each for several seconds at a time. By doing this, she makes a conspicuous sucking sound as she extracts and swallows the juice, spitting out most of the remaining fiber. This continues for 17 minutes, with short breaks as she consumes the pith of each branch in the same manner.”
Dr. Michael Huffman’s description of Chausiku documents a fascinating example of animal self-medication what some call "zoopharmacognosy." In this instance, the chimpanzee, weak, clutching her back in pain, and listless, was ingesting the leaves of the plant, Vernonia amygdalina, to purge an intestinal parasite. She recovered by the next morning.
Vernonia leaves have since been found to contain over a dozen potential anti-parasitic compounds. Chimps in this region commonly suffer infestations of parasites like Strongyloides fuelleborni (thread worm), Trichuris trichiura (whip worm), and Oesophagostomum stephanostomum (nodular worm). They have somehow stumbled onto a treatment that they administer themselves.
Chimpanzees have inhabited earth for over 6 million years. Who knows how long they and other primates have practiced some form of self-medication.
If chimpanzees can do it, I believe that we, as human primates, can also practice a similar form of self-directed health-- homopharmacognosy?