Originally from southern Mexico (particularly from Chiapas and Veracruz), Central America and northern South America, papaya is now grown in most tropical countries.
In cultivation, it grows rapidly, fruiting in three years. However, it is highly sensitive to frost and limits its production to tropical climates.
Papain, a protease found in papaya, is used to soften meat and other proteins, as is currently practiced by Native Americans and the people of the Caribbean region. It is now included as a component in some meat tenderizers.
Papain has been used in alternative cancer therapies such as Dr. Kelley’s Metabolic Diet in which enzymes and digestive proteases supposedly “eat” and neutralize cancer cells.