Research shows that papain, a compound found in papaya fruit trees, may serve as a useful supplementary therapy in the treatment of multiple myeloma.

Papain is an enzyme that breaks down proteins. One such protein, called fibrin, makes up the protective layer of cancer cells. Papain degrades fibrin and damages this protective layer, making the cells more susceptible to immune response or chemotherapy. The compound also hinders tumor growth and prevents it from spreading to other parts of the body.

Papaya plants contain high concentrations of papain, not only in the fruit, but also in the stem, leaves, fruit skin, and seeds. The compound has a toxic effect on plant-eating insects, protecting the unripe papaya from the insects. It decreases naturally in concentration as the fruit ripens.

Synthetically, papain is combined with the enzymes trypsin and chymotrypsin in an oral enzyme product called Wobe-Mugos E. Wobe-Mugos E has been used in Europe to bolster chemotherapy since 1977.  Since then, studies have been conducted to verify the treatment efficacy of Wobe-Mugos E in multiple myeloma.

Scientists at the University of Brastislava’s Clinic of Hematology and Transfusion Medicine in the Slovak Republic determined that multiple myeloma patients undergoing chemotherapy achieved a greater remission response if they were supplemented with Wobe-Mugos E for more than six months, compared to patients who were not.

Patients in the Wobe-Mugos E group received two tablets of the oral enzyme daily for one year after starting chemotherapy, then one tablet daily for the remainder of their treatment. Supplementation with Wobe-Mugos E took place for a median of 41 months. Among patients who received Wobe-Mugos E, 97.6 percent achieved complete response, partial response, or disease stability after chemotherapy, compared to 69.7 percent of patients who received a placebo.

In addition, the median survival for Stage 3 patients nearly doubled with Wobe-Mugos E supplementation. The therapy proved safe, causing gastrointestinal symptoms in only 3.6 percent of patients. However, because group assignments were not random, the study’s results may have been influenced. Scientists expressed enthusiasm but recommended further evaluation. The journal Cancer Chemotherapy and Pharmacology ^[1] (abstract) published their results in June 2001.

Several accounts from cancer survivors suggest that eating papaya offers the same antitumor benefits as synthetic forms of papain. In a book entitled Cancer: The Complete Recovery Guide ^[2], author John Chamberlain cites the story of a woman whose friend overcame stomach cancer in six months by juicing the skin of unripe papaya. He provides a recipe that explains how to do so.

In food, papain poses little to no health risk. Medicinal doses are also safe for most adults to consume, although patients may experience throat and stomach irritation. In instances of pregnancy, allergy to kiwi or figs, and blood clotting disorders, papain may pose a health risk and should be avoided. When in contact with the skin, raw papain may cause blistering or irritation.

Dietary supplements containing papain are available on the market. Patients should be advised that the Food and Drug Administration (FDA) does not require the manufacturers of dietary supplements to register their products before they enter the market. However, the FDA does monitor the supplements' safety once they are on the market. Tips on how to choose supplements are available on the FDA ^[3]’s Web site.

While little research has been done to illuminate the effects of papain in treating multiple myeloma, the enzyme and the fruit in which it is found offer a promising development in the fight against the disease, and their effects should be further evaluated.

In the meantime, patients should consult their physicians before taking papain supplements or changing their dietary patterns to include papaya fruit or juice.