Papaya contains digestive enzymes

Papaya fruit offers not only the luscious taste but is a rich source of antioxidant nutrients such as carotenes, vitamin C and flavonoids; the B vitamins, folate and pantothenic acid; and the minerals, potassium and magnesium; and fiber. Together, these nutrients promote the health of the cardiovascular system and also provide protection against colon cancer. The fruit is valued for its proteolytic enzymes including papain, which is used like bromelain, a similar enzyme found in pineapple, to treat sports injuries, other causes of trauma, and allergies. The milk like juice from unripe fruit called latex, contains the most concentration of papain, enough some people say to remove freckles.

Papaya leaf is used in herbal medicine to remove intestinal worms. Papaya leaf has less of the protein-dissolving papain than the fruit, so it is less likely to "dissolve" the worms, but it contains tannins that the fruit does not. These tannins protect the intestine from reinfection by "tanning" proteins in the lining of the intestinal wall so that worms cannot attach themselves. ^{Mountain Rose Herbs (2008-06-23)}