Seven inches long, first cousin to the earthworm but with livelier ambitions, Ascaris lumbricoides is one of the commonest parasites found in the intestines of man. The worms, which usually plague children more than adults, enter the body in infected vegetables, may cause diarrhea, colic, convulsions. Standard anthelmintic (worm-killer) for ascarids is bitter oil of chenopodium (wormseed oil), usually given in capsule form. Last week in Science, Chemists Julius Berger and Conrado Frederico Asenjo of the University of Wisconsin stood up for a primitive worm-killer which is sweeter, cheaper, and just as powerful: fresh pineapple juice.
Pineapple juice has long been swigged by wormy natives of India, but until the Wisconsin scientists put it to laboratory test, its anthelmintic virtues were unknown to modern medicine. The scientists dropped a pair of living ascarids, taken from hogs' intestines, in a jar of juice freshly squeezed from a Cuban pineapple. Another group of worms was doused in "heat-inactivated" pineapple juice; a third in plain salt water. At the end of 24 hours the worms in the heated juice and the salt water were "very lively and active." But those in the fresh pineapple juice were "completely digested" (dead). Reason: fresh pineapple juice contains an enzyme, or ferment, which acts like a corrosive acid on worms. No worm-killer is canned pineapple juice, said the scientists, for the boiling necessary to preserve the juice destroys the anthelmintic enzyme.