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Medicine: The Great Papaya Fracas

3 minute read
TIME

Does the fruit extract really help back pain ?

The papaya is a wondrous fruit—abundant, tasty and nutritious. A papaya extract is the active ingredient in supermarket meat tenderizers, and the papaya has long been used by traditional healers to treat illnesses ranging from hepatitis to gonorrhea. Now an extract from the fruit has become the center of a growing medical controversy. Despite doubts expressed by many U.S. experts, hundreds of U.S. citizens are traveling to Canada to be treated with a papaya enzyme for what is commonly called a slipped disc.

The Canadian migration stems from a discovery by Dr. Lyman Smith, an orthopedic surgeon in Elgin, Ill. In the early 1960s he found that injections of papain, a simple papaya extract, dissolved the nuclei of discs between the vertebrae of rabbits. As a result, the discs shrank. If papain had the same effect on human slipped discs, he reasoned, they would shrink back into place.

Smith sold his patent rights to Baxter Travenol Laboratories of Deerfield, Ill., which extracted from papain another enzyme, chymopapain, that was more potent and less toxic. Baxter Travenol trade-named its product Disease and obtained U.S. Food and Drug Administration approval in 1963 for its use as an investigational new drug for humans. In twelve years doctors treated some 15,000 patients, and reported that symptoms were relieved in most cases. Meanwhile, Baxter Travenol had applied to the FDA for approval of Disease as a prescription item for any licensed physician to use.

But in 1975, when some still disputed new tests seemed to show that Disease had no more effect on slipped discs than did a placebo, Baxter Travenol withdrew its application and stopped producing the enzyme. Furthermore, because the company did not submit a new application to cover investigational treatments, use of Disease became illegal in the U.S.

But it is still legal in Canada, and some U.S. orthopedists are referring their patients to medical centers there. A notable example is Dr. Howard Bates Noble, a Chicago orthopedic surgeon who has sent 20 to 25 patients to Canada—and needed help himself. As he puts it: “Faced with the choice of surgery or chymopapain, I decided to put my back where my mouth was.” So he referred himself to Dr. Ian Macnab at Toronto’s Wellesley Hospital, who injected him with chymopapain last year. Now, Noble says, his back troubles have disappeared.

Most patients from south of the border tell much the same story. Arriving at a Canadian medical center armed with their spinal X rays, they usually need to spend only two days in a hospital. Almost unanimously, they give glowing testimonials to the benefit they have received. Indeed, if the injections are as curative as supporters claim, they would banish the need for costly operations for many of the estimated 170,000 Americans who each year undergo disc surgery.

But does the cure really come from chymopapain? Many U.S. doctors have their doubts. They note that by far the commonest forms of low-back pain involve muscles, ligaments or tendons rather than discs; these can usually be treated best with rest, physiotherapy and regular exercise. Many of the claimed chymopapain cures, the critics say, are the result of a dramatic placebo effect.

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