The papaya, a tropical tree-like plant, was originally cultivated in Mexico and can grow more than 30 feet tall. The papaya plant bears a versatile fruit that is eaten both ripe and unripe. According to "Papaya the Medicine Tree," the entire papaya plant -- roots, leaves and fruit -- offers medicinal value. Young papaya leaves are eaten like a vegetable in some cuisines, and papaya leaf tea has a variety of purported medicinal effects.
Papaya leaf tea might prove effective as a cancer preventative and treatment, according to a study published in the February 2010 issue of the "Journal of Ethnopharmacology." In the tissue culture study, papaya leaf tea reduced inflammation and activated immune system toxic effects toward cancer cells, inhibited tumor cell growth and stimulated genes that modulate the immune system's anti-tumor effects. The researchers concluded that the results of their preliminary study indicate the immune-modulating properties of papaya leaf tea may prove to useful in treatment and prevention of diseases, including cancer, allergies and as a component in some vaccines.
Papaya leaf tea protected against gastric ulcer in a study on laboratory animals published in the September 2008 issue of the "West Indian Medical Journal." In the study, papaya leaf extract reduced ulcer severity and showed strong antioxidant effects. Papaya leaf extract also decreased oxidized lipids and increased antioxidant activity within red blood cells. Researchers concluded from this preliminary study that papaya leaf tea shows potential for the treatment of gastric ulcer and oxidative stress on the stomach.
The enzyme papain in papaya leaves assists in the digestion of proteins and is useful for treating gastrointestinal disorders, according to the book "The Complete Herbal Guide: A Natural Approach to Healing the Body." Papaya leaf tea can alleviate heartburn discomfort and is an appetite stimulant. Papaya leaf tea may also help digest the wheat protein gluten, which is difficult for some people to digest and causes an autoimmune condition known as celiac disease. This area still needs more research, so people with celiac disease should not use papaya leaves to treat their condition.
The enzyme papain in papaya leaf has been known to cause allergic reactions in some people, according to a study published in the September 2008 issue of the journal "Ugeskrift for Laeger." The report documented a breakout of allergic symptoms in 10 out of 22 employees at a research laboratory who were exposed to papain dust. The workers developed symptoms of itchy eyes and runny nose. Improved hygienic conditions and proper ventilation solved the problem.