Papaya benefits: there is a phase III trial — but of the leaf extract, not the fruit

Key benefits

1. 01Not established

   The phase III trial of leaf extract — and why it does not carry across to the fruit

   2026, JCO Global Oncology.

   Design	Phase III, triple-blinded, randomised, placebo-controlled, multicentre
   Dates	March 2020 to October 2024
   Allocation	219 randomised 2:1, 198 analysed (extract 129, placebo 69)
   Participants	patients with chemotherapy-induced thrombocytopenia
   Intervention	papaya leaf extract, until platelets reached 75,000, a transfusion was needed, or day 10
   Primary outcome	proportion reaching platelets above 75,000 by day 4

   The results:

   Analysis	Extract	Placebo	p
   Modified ITT	59%	44%	0.042
   Per protocol	64% (83/129)	48% (33/69)	0.034
   Dose reduction or delay in later chemotherapy (grade 2)	25%	43%	0.033

   There were no grade 3 or grade 4 treatment-related adverse events.

   The quality of this trial deserves acknowledgement first. A triple-blinded, placebo-controlled, multicentre phase III trial is a standard rarely seen in food-related research. It is far stronger than the evidence behind most entries on this site.

   So why is the grade "not established"?

   Because this entry is about papaya fruit, and the trial used leaf extract.

   Three things differ.

   First, the part of the plant. Leaf and fruit come from the same plant but differ in composition. It is like tomato leaf against tomato fruit — and tomato leaf does carry alkaloids the fruit does not.

   Second, the form. Extraction selects and concentrates particular compounds. It is the same problem set out in this site's celery entry.

   Third, the population. This trial studied patients whose platelets had fallen from chemotherapy. It is not a trial of what happens to someone whose platelets are normal.

   A word on dengue. There is a tradition of using papaya leaf for the thrombocytopenia of dengue, and research in that direction. But this entry is about the fruit, so that evidence is not carried over as a benefit of the fruit.

   If you are considering papaya leaf tea or leaf extract products, those are different from the food this entry covers. And if you are in chemotherapy or have a blood disorder, speak to your clinician. Something that acts on platelets can also affect bleeding and clotting.

   The honest conclusion:

   • Papaya leaf extract sped up platelet recovery in chemotherapy patients — that is what the phase III trial showed
   • Evidence that eating papaya fruit raises platelets is something this site could not find
   • So the grade for the fruit is "not established"

   [1]
2. 02Nutrition data

   60.9 mg of vitamin C, 1,830 µg of lycopene — what the fruit actually holds

   Per 100 g of raw papaya:

   • Vitamin C 60.9 mg
   • Lycopene 1,830 µg
   • Folate 37 µg
   • 43 kcal, carbohydrate 10.8 g, sugar 7.82 g, fibre 1.7 g
   • Potassium 182 mg, magnesium 21 mg, calcium 20 mg
   • Vitamin A 47 µg RAE, beta-carotene 274 µg
   • Protein 0.47 g, fat 0.26 g, sodium 8 mg
   • Vitamin E 0.3 mg, vitamin K 2.6 µg

   The 60.9 mg of vitamin C is the most useful figure here. Against an adult requirement of around 100 mg, 100 g covers more than 60%. The edible part of a medium fruit is about 300 g, so half of one clears the day.

   Fruit	Vitamin C (100 g)
   Guava	228 mg
   Kiwi	92.7 mg
   Papaya	60.9 mg
   Orange	53.2 mg
   Mango	36.4 mg

   The 1,830 µg of lycopene is worth noting too. Raw tomato holds about 2,570 µg per 100 g. Papaya's orange flesh is that pigment, the same family as in watermelon and guava.

   But there is no daily value for lycopene, and this site does not print a percentage where no reference exists. What has been confirmed in people from eating lycopene amounts to what is written in the tomato entry, and no more.

   At 43 kcal it is low among fruits — mango is 60, banana 89. Sugar at 7.82 g is low too, about half of mango's 13.7 g or banana's 12.2 g.

   Fibre, though, is only 1.7 g, against guava's 5.4 g.

   Choosing. It is ready when the skin turns from green towards yellow and it yields slightly to a fingertip. Fully green means unripe.

   Ripen at room temperature. The fridge stops it where it is. Chill it after it ripens.

   The seeds are not usually eaten. They taste peppery, and for reasons set out below, do not make a habit of large amounts.

   Unripe green papaya is a different food. Southeast Asian cooking uses it in salads and stir-fries, and it carries more latex than the ripe fruit.

3. 03Early research

   The seed and intestinal parasites — a small 2007 pilot study

   There is a tradition of using papaya seeds against intestinal parasites, and one trial has tested it.

   2007, Journal of Medicinal Food. A randomised trial giving dried papaya seeds to people with intestinal parasitosis. The paper calls itself a "pilot study".

   How to read that.

   • A pilot study is a step towards designing the real trial. It is not used to settle a question
   • It was small
   • This site could not find a larger trial since that confirmed the result
   • And what it used was dried seeds, not the fruit

   If you suspect intestinal parasites, get diagnosed and treated. Effective antiparasitic drugs exist, and they are safe and certain. This site does not recommend papaya seeds for deworming.

   There are reasons not to eat large amounts of the seeds, too.

   Papaya seeds contain benzyl isothiocyanate — the source of the peppery taste — and safety data for large quantities is not adequate. Animal research has also reported effects of high-dose papaya seed on sperm. That has not been confirmed in people, but there is no reason to eat large amounts daily beyond culinary use.

   To summarise:

   • Confirmed: the composition — vitamin C 60.9 mg, lycopene 1,830 µg, folate 37 µg
   • Confirmed for a different part of the plant: leaf extract sped platelet recovery in chemotherapy patients (phase III)
   • Preliminary: dried seeds and intestinal parasites (small, 2007)
   • Not confirmed: that eating the fruit raises platelets

   [2]
4. 04Not established

   The digestion claim — and warnings about allergy and pregnancy

   Digestion is the claim most often attached to papaya, backed by papain, a protein-digesting enzyme.

   It is true that papain breaks down protein. It is used as a meat tenderiser. And it is highest in unripe green papaya, falling as the fruit ripens.

   But this site could not find a clinical trial that fed papaya, measured digestive function and compared against a control.

   The same structure is set out in this site's mango and fig entries. Containing an enzyme and improving digestion when a person eats it are separate claims. An enzyme swallowed meets stomach acid and digestive enzymes first.

   And three warnings have to go here.

   First, cross-reaction with latex allergy.

   Papaya contains latex components, and people allergic to natural rubber latex have been reported to react to papaya. This is called latex-fruit syndrome, and banana, avocado, kiwi and chestnut are on the same list.

   If latex gloves have ever given you a reaction, be careful with your first papaya. Stop and seek care if your mouth itches or swells.

   Second, unripe papaya in pregnancy.

   The latex in unripe green papaya has a record of being linked to uterine contraction. It is not settled in people, but there is no reason to take a risk where the data is thin.

   • Fully ripe papaya is generally regarded as not a problem
   • Unripe green papaya, and salads and stir-fries made from it, are safer avoided in pregnancy
   • Papaya leaf tea and leaf extract are also not recommended in pregnancy

   Third, papain enzyme supplements. These are not the fruit but an extracted, concentrated product, and there are reports that they may affect blood clotting. If you take an anticoagulant such as warfarin, speak to your clinician.

   Eating it as fruit is generally safe. The warnings above concern the unripe fruit, the seeds, the leaf, and extracts.

How to eat it well

What to watch out for