Papaya Extract Side Effects

The juicy, bright and orange pulp from papaya fruit is an excellent source of several vitamins and fiber. Christopher Columbus allegedly called it the "fruit of the angels" when he first encountered it, and traditional medical practitioners in South America have used it for pain, inflammation and infections. Although papaya extract is showing great promise as an anti-tumor treatment, it also has some potentially negative health effects on the body.

Allergic Reactions

When they are not ripe, papayas release substances called chitinases, which have properties similar to latex. For this reason, if you have an allergy to latex, you should avoid papaya because it could provoke skin irritation at the very least. It could also possibly induce rhinitis, asthma and a severe allergy that is accompanied by swelling, dizziness and breathing difficulty. Fruit processed with ethylene gas increases the effects of the chitinases, so you may reduce your chance of an allergic reaction by choosing organic produce and by cooking the fruit, which deactivates the enzymes.

Drug Interactions

Papaya may affect the blood's ability to clot, which can lead to excessive bleeding if you're taking a blood thinner like Coumadin, Heparin or Lovenox. If you choose to take papaya extracts while on such medications, make sure you have your PT/INR blood clotting levels checked regularly.

Gastrointestinal Side Effects

Papaya contains an enzyme known as papain, which is used in Adolph's Meat Tenderizer. There have been reports of large doses of papain sometimes causing stomach upset. A 1987 issue of "Journal of Clinical Gastroenterology" discussed the use of the papain-containing tenderizer to treat patients who had meat fragments stuck in their esophagus. This standard treatment for such cases caused damage to the esophagus.

Heart Side Effects

One of the major alkaloids in papaya, carpaine, can cause paralysis, decrease heart rate and cause nervous system problems in high doses. A 2001 study at the McMaster University Department of Biology in Canada found that high doses of papaya seed extract had toxic effects in a laboratory animal, preventing normal contractions of the carotid artery. Although it's difficult to consume quantities of papaya extract large enough to cause these effects, you should use caution in taking papaya extracts and stick with small doses if you have heart problems or nervous system medical conditions.

Side Effects During Pregnancy

Although there hasn't yet been any definitive clinical research to say whether papaya should be avoided by pregnant women, there is some preliminary evidence papaya may be toxic to a fetus. In a 1978 study reported on Drugs.com, the main danger in pregnancy seems to be with unripe or semi-ripe papaya that contain higher levels of latex and may cause uterine spasms. There are also anecdotal reports summed up in a 1994 article published in "Asiaweek" that papain suppresses progesterone and works like a contraceptive, and that abortion may be induced by eating unripe papaya for three consecutive days.