Papaya - Carica papaya

Common Names: Papaya, pawpaw, tropical melon, tree melon, papaw, mamón, lechosa, fruta bomba, melon papaya, melon tree, kostela, papaye, le papayer, melon des Tropiques, papaya melon, papayón, Qovunagaci, Die Papaja, la papaia, Harilik papaia, Carica papaya

Latin Name: Carica papaya

Origin: Africa, Asia, Australia, South America, North America

Short Introduction

Today, papaya is cultivated worldwide in tropical and subtropical regions. Most imported papayas come from India, Indonesia, Africa, Hawaii, Florida, California, Puerto Rico, Latin and South America. In 2013, India led global production with 5.5 million tons, followed by Brazil (1.6 million tons), Indonesia (0.9 million tons), Nigeria, and Mexico (0.8 million tons each).

The main harvest is at the beginning of summer or autumn. Papaya is commercially propagated using seeds and is harvested in both green and ripe states, often left to ripen after picking. When fully ripe, its flesh is sweet, juicy, and reminiscent of watermelon.

A single plant can yield between 30 and 150 fruits (up to 100 kg). The plant grows rapidly, can reach up to 2 meters in six months, and starts fruiting within three years. On average, papaya lives up to 25 years, although plantations are typically renewed every 6–8 years.

Carica papaya is cold-tolerant, but temperatures below -2°C can be highly damaging or fatal. In Florida and California, commercial cultivation is limited to the southern regions and private plantations in Los Angeles, San Diego, and around Orange County. Papaya prefers sandy, well-drained soils—standing water can kill the plants.

Papaya's popularity among tropical fruits is rising, currently ranking fourth globally in production behind banana, orange, and mango. In several developing countries in Asia and Latin America, papaya farming and trade have become vital economic factors, employing and supporting thousands of people.

Detailed Description

The fourth most popular fruit in the world, renowned for its benefits far beyond parasite defense.

Botanical Information

Papaya (Carica papaya) is a large, heat-loving plant resembling a tree, typically reaching 5 to 10 meters in height. It has a single, woody, unbranched stem which is actually a pseudo-trunk up to 30 cm in diameter, hollow, and rich in a dense network of supportive fibers—an adaptation for wind resistance.

The leaves are spiral, large (around 60 cm), deeply palmate-lobed, and grouped in a rosette atop the stem. They are deciduous, yellow-green, with palmate blades and serrated lobes. The plant contains latex-producing ducts throughout.

The flowers, similar to plumeria but smaller and waxier, grow in leaf axils. Flowers may be bisexual or unisexual, and plants may be monoecious or dioecious—almost all commercial varieties are bisexual and self-fertile. Male flowers only produce pollen, while female flowers produce fruit only if pollinated. Bisexual flowers are self-pollinating.

The fruit matures to a large, berry-like form measuring 15–50 cm long and 10–35 cm wide (depending on the cultivar), similar in appearance to a squash. The fruit is ripe when soft to the touch (like avocado) and the skin turns amber-yellow to orange. Inside, the juicy flesh is 3–4 cm thick, vibrant yellow to red-orange. In the center are 1000–1500 gray-black, peppery-tasting seeds, about 5 mm in diameter.

Origin and Distribution

Papaya is believed to be native to southern Mexico (Chiapas and Veracruz), Central America, and northern South America. It is now grown globally across tropical and subtropical regions such as the Caribbean, the USA (Florida, California), several African countries, India, Malaysia, Indonesia, and the Philippines.

There are two main variants: Hawaiian and Mexican papaya. Though they differ in size, their nutritional value and phytochemical profiles are similar. Christopher Columbus dubbed papaya the "fruit of the angels."

Usage / Dosage

Papaya is most often enjoyed as a fresh fruit, either ripe or unripe, and used in juices and beverages. Its leaves and stems are eaten as vegetables, and the fruit features in sauces, sweets, cakes, and ice cream.

In Southeast Asia, green papaya is an essential ingredient in Thai salads (such as som tam) and sauces (kaeng som), while in Indonesia, unripe fruit and leaves are mixed into salads (lalab).

Papaya seeds are sometimes used as a pepper substitute, and the leaves are consumed as a leafy vegetable. Export of whole fruits is limited due to disease and other restrictions.

The latex collected from gently scoring unripe papaya is processed into "raw papain", a meat-tenderizing enzyme now widely available in supermarkets. Traditionally, papaya has been used by South American cooks to tenderize tough meats, a practice that continues today. Papain is also used to prevent milk from curdling and to aid digestion due to its protein-digesting enzymes. Beyond culinary uses, papain features in American beer production, chewing gums, and a variety of cosmetic products.

Papain and chymopapain are two enzymes recognized for powerful digestive support—commonly used as stomachics and digestives. In certain countries, carican and chymopapain are part of gluten-detoxifying treatments for those with intolerance. Benzyl isothiocyanate, another substance in papaya, is a significant inducer of glutathione S-transferase, a key enzyme in cellular detoxification.

One study evaluated the effects of 3 g of fermented papaya daily for two months in both healthy volunteers and type 2 diabetics. Results showed significant glucose-lowering potential in both groups, even allowing some patients to reduce or discontinue other medications (Danese C. et al., 2006). This suggests papaya enzymes may enhance the hypoglycemic effect of conventional antidiabetics when used together.

Fresh papaya juice has demonstrated the ability to lower blood cholesterol and triglyceride levels within 24 hours. Regular use of papaya extracts significantly reduced LDL and triglyceride values compared to controls, emphasizing the fruit's antihyperlipidemic potential.

An aqueous extract of papaya fruit at 10 mg/kg was comparable to hydrochlorothiazide in diuretic effect in animal studies, and ethanolic extract of unripe papaya demonstrated strong antihypertensive potential, outperforming hydralazine in hypertense subjects in preclinical models.

Active substances in papaya have been widely studied for their gastrointestinal and antiparasitic effects. Benzyl isothiocyanate and papain display in vitro antihelminthic activity, with benzyl isothiocyanate considered the dominant compound due to papain's instability in gastric acid. Animal and clinical studies have shown papaya seed extracts to be effective against a range of gastrointestinal parasites, including Ascaris lumbricoides, Necator americanus, Entamoeba histolytica, Giardia lamblia, Strongyloides spp., and Trichuris spp..

Papaya's proteolytic enzymes may also immobilize and destroy microorganism organelles, boosting host defense, especially when phagocytes are stimulated. Papaya contains the alkaloid carpaine, which has demonstrated moderate antibacterial action. Studies have confirmed papaya’s antibacterial effect against Bacillus subtilis, Bacillus cereus, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Shigella, Proteus vulgaris, Enterobacter cloacae, and Klebsiella pneumoniae.

One in vivo study suggests that regular papaya consumption may decrease the risk of contracting human papillomavirus (HPV).

Papaya latex and extracts have shown benefit in wound healing—including burns, pressure ulcers, edema, and inflammation—both in animal models and human clinical use. Papaya is often used in African hospitals to aid wound granulation and prevent infection, and topical papain is available in the US for debridement.

Enzymes from papaya are sometimes used to treat swelling and inflammation after surgery or injuries and may also aid in inflammatory diseases of the intestines, liver, eyes, and genitals.

Chymopapain was once approved for injection therapy in herniated discs when standard treatments failed. Animal studies have confirmed papaya's potential to prevent and heal gastric ulcers, and its antioxidant effects match those of vitamin E, as shown in human trials with both seniors and patients with chronic hepatitis C.

Folk Medicine

Papaya has been used in traditional medicine for centuries. Sap was used for warts, calluses, swelling, cancerous lesions, and damaged skin; unripe fruit as a mild laxative, diuretic, and to stimulate lactation and labor. Ripe fruit has been used for rheumatism and alkalizing urine. Seeds are used against intestinal worms. Papaya is linked with reduced risks of urinary stones and colorectal cancer in folk medicine, and in some developing countries is promoted as a support for diabetes, antimicrobial antiseptic, diuretic, antiparasitic, anti-inflammatory, antihypertensive, and antihyperlipidemic purposes, as well as for wound healing and intestinal parasite infections. Papaya is also commonly used for indigestion, bloating, diarrhea, and vomiting.

Restrictions and Safety

Some individuals may have allergies to papaya or papain, especially those allergic to latex. Papaya should be discontinued two weeks before surgery as a precaution. While no drug interactions are documented, papain can affect INR values in patients on warfarin or other anticoagulants—always consult a healthcare professional before use.

Though papaya was once considered potentially unsafe during pregnancy due to old reports, subsequent studies found it to be non-toxic unless high concentrations of latex are consumed, which may cause uterine contractions. Animal studies have not established lethal toxicity in reasonable doses.

Active Compounds

Unripe papaya contains papain and chymopapain, as well as a variety of cysteine endopeptidases and other enzymes. Ripe fruit does not contain significant amounts of these enzymes. Papaya is rich in vitamin A, fiber, folate, sodium, vitamin C, and various antioxidants. It is virtually fat- and cholesterol-free. Minor constituents include alkaloids, flavonoids, saponins, tannins, anthraquinones, sugars, phenolic compounds, cardenolides, and steroids, as well as beta carotene, vitamins B2, B3, and B6. Papaya seeds contain prunasin, sanigrin, caricin glycosides, and the enzyme myrosinase.

Traditional Dosage

Dosages vary widely depending on the intended use and the type of preparation. One study used 20 ml aqueous extract of dried papaya; others used similar doses. In the US, prescription topical ointments containing papain are used for debridement. One study used 4 grams of dried seeds in 20 ml of honey for antiparasitic effect. No standardized systemic dosage is established—folk medicine suggests intake "according to taste and need." Dosage should be personalized based on age, health status, medications, and therapeutic goals.