A pineapple is not one fruit. The plant produces up to about 200 flowers, and their ovaries swell and merge into a single compact fruit, which botanists call a multiple fruit. It also stops ripening once it is picked, so growers have to harvest it ready to eat.
Fresh pineapple holds bromelain, a mix of protein-digesting enzymes. It is the likely reason a few bites can leave your mouth feeling raw or tingly, though researchers say the effect is not well studied. It is also why fresh pineapple stops gelatin from setting: the enzymes cut the collagen proteins in gelatin into pieces too small to form a gel. Heat destroys bromelain, so cooked or canned pineapple does not do this.
Most research on pineapple is really research on bromelain, taken as a pill made mostly from the stem. A serving of the fruit probably holds much less than a pill does, so those results may not carry over to eating pineapple. The studies below label bromelain supplements plainly, and within each level of evidence the studies of the fruit come first.
Health benefits of pineapple
The top findings from 23 studies, strongest evidence first
What the stars mean
- Strong. Several randomized trials, pooled in a meta-analysis, point the same way, or regulators (FDA or EFSA) have approved the claim.
- Moderate. Good randomized trials support it, but there are fewer of them, or their results vary.
- Limited. Small, short or single trials, or mixed results. Promising, but it needs confirmation.
Population and lab studies get no stars: they show a link or a mechanism, not proof.
How we rate evidence →- ★★Slightly less pain with bromelain supplementsBromelain is a pineapple extract, and these were supplements, not the fruit. Across 9 trials, pain scores were 0.27 points lower than in controls.
- ★★Bromelain pills eased pain after wisdom tooth surgeryIn two reviews of 6 trials each, bromelain pills lowered pain by day 7 after wisdom tooth surgery. Neither found an effect on jaw stiffness, and they disagreed on swelling.
- ★Fewer infections in children, in one trialIn Filipino school children, canned pineapple (140 g or 280 g) for 9 weeks went with fewer viral and bacterial infections than none. It was one trial, using canned fruit.
- ★Higher melatonin levels after eating pineappleJuice from 1 kg of pineapple raised blood melatonin, the sleep hormone, from 48 to 146 pg/mL within 2 hours in healthy men. In another study a urine marker of melatonin rose 266%, but neither tested sleep.
- ★High glycemic index, above papaya and watermelonIn 10 healthy volunteers, pineapple scored 82 on the glycemic index, a measure of how fast a food raises blood sugar. Papaya scored 58, watermelon 55 and durian 49.
All 23 studies, strongest evidence first
Bromelain supplements reduced pain slightly compared with controls in a review of clinical trials
Systematic review of 54 articles with a meta-analysis of 39, on oral and topical bromelain extracts, not the fruit. The pain score difference was 0.27 points lower (range 0.08 to 0.45) across 9 trials. Topical bromelain cut the time to complete wound debridement by 6.89 days. The authors rate the studies as moderate quality, found no benefit for cardiovascular disease, and list flatulence, nausea and headache as side effects.
Bromelain pills taken after wisdom tooth surgery reduced facial swelling and, a week later, pain in a meta-analysis, but not jaw stiffness
Meta-analysis of 6 randomized trials of bromelain supplements against placebo after mandibular third molar surgery. Swelling was lower at 2 to 3 days (standardized difference 0.24) and at 7 days (0.54), and pain was lower at 7 days (0.54) but not earlier. Trismus, a stiff jaw, did not change. The authors call the relief moderate.
A second meta-analysis of bromelain pills after wisdom tooth surgery found less pain and better quality of life, but no effect on swelling
Meta-analysis of 6 randomized trials of bromelain supplements after third molar surgery. Pain was lower at 24 hours (standardized difference 0.49) and at 7 days (0.52), and appearance, social isolation and sleep scored better in the first week. Unlike the review above, it found no evidence of an effect on swelling or trismus. The authors say higher-level head-to-head trials are needed.
Eating canned pineapple for 9 weeks went with fewer viral and bacterial infections in Filipino school children
Randomized controlled trial in 98 school children, comparing no pineapple with 140 g or 280 g of canned pineapple. Granulocytes, a type of white blood cell, rose 0.77 to 26.61% in children of normal weight and 14.95 to 34.55% in underweight children. Del Monte Philippines supplied the canned pineapple and, according to the authors, had no role in the study. It was one trial, with canned fruit.
Drinking the juice of 1 kg of pineapple raised blood melatonin from 48 to 146 pg/mL within 2 hours in healthy men
Crossover study in 12 healthy men who also tried orange juice and bananas, which raised melatonin by similar amounts. Blood antioxidant capacity rose 7 to 14% by one test (FRAP) and 6 to 9% by another (ORAC), in step with melatonin. It measured blood levels only, not sleep or health.
Eating pineapple raised a urine marker of melatonin by 266% in healthy volunteers
Crossover trial in 30 healthy volunteers who ate six tropical fruits one at a time, a week apart. The marker rose 180% after banana and 47% after orange. It did not test sleep, and the authors call for further study of any clinical effect.
Pineapple had a high glycemic index of 82 in 10 healthy volunteers, above papaya, watermelon and durian
Volunteers ate portions with 50 g of available carbohydrate on separate mornings after fasting, with glucose as the reference. Glycemic index was 58 for papaya, 55 for watermelon and 49 for durian. Each fruit was tested once per person, and the authors note the result depends on the portion sizes taken from food tables.
Adding 1 liter of pineapple juice to a reduced bowel prep raised adequate colon cleaning to 80% from 63.9% with the prep alone
Randomized trial in 126 people having a colonoscopy, given 4 liters of the standard prep, 2 liters, or 2 liters plus the juice. The juice group cleaned better on the right side and in the transverse colon, and all three regimens were tolerated about equally. The 4-liter group reached 68.1%. This shows an effect on colon cleaning, not on health.
Drinking pineapple juice for 4 days raised the body’s exposure to the painkiller celecoxib by 60%
Two randomized crossover studies gave a single dose of celecoxib or of montelukast, an asthma drug, after 4 days of water or pineapple juice. Peak levels of celecoxib rose 40%, and exposure to montelukast rose 48%. There were no noticeable side effects. The abstract gives no group size or juice amount and does not say what this means for health.
Pineapple fiber powder, not the fruit, for 14 days raised 6 species of gut bacteria in adults
Placebo-controlled trial in 60 adults eating food with 5 g of fiber from placebo, green banana powder or pineapple fiber powder, with stool tests at baseline, day 7 and day 14. Some authors work for a Dole ingredient business, and others for the microbiome company that ran the tests. It tested an ingredient, so it may not apply to whole pineapple.
A review of 7 trials found the effect of bromelain supplements on inflammation inconsistent
Systematic review of 7 randomized trials of bromelain alone or with other compounds. Most reported lower inflammation markers, but the authors call the overall effect inconsistent because people, doses, timing and markers differed. Bromelain alone ranged from 200 to 1050 mg a day for 1 to 16 weeks. Eleven people had side effects, mostly gastrointestinal, and two stopped.
Bromelain supplements, 400 mg a day for 8 weeks, lowered ulcerative colitis activity scores more than placebo, but quality of life did not change
Triple-blind randomized trial in 70 adults with mild-to-moderate ulcerative colitis. The symptom score (SCCAI) fell 3.29 points on bromelain and 1.11 on placebo, while quality-of-life scores changed about the same in both groups. The groups differed in gender, and it was a single trial.
Bromelain supplements, 800 mg a day for 12 weeks, did not improve knee osteoarthritis scores more than placebo
Double-blind trial in 47 people with moderate to severe knee osteoarthritis, of whom 31 finished (14 on bromelain, 17 on placebo). The total WOMAC score did not differ between groups, and side effects were mild. The authors say its limitations call for a follow-up study.
Bromelain supplements, 200 mg every 8 hours, lowered swelling after eyelid surgery on days 3, 7 and 11
Triple-blind placebo-controlled trial in 46 people having upper eyelid surgery (23 per group), who took bromelain or starch capsules for 2 weeks. Bruising scores were lower only on day 3, and side effects did not differ. The authors call for larger multicenter trials.
A pineapple extract rich in bromelain, or purified bromelain, for a week after wisdom tooth surgery cut the need for ibuprofen compared with placebo
Three-arm randomized placebo-controlled trial in 42 people, who took the freeze-dried pineapple extract, purified bromelain or placebo from the day of surgery for 7 days. Pain and swelling were lower in both active groups, and the drop in trismus was not significant. The authors say larger studies are needed.
Bromelain supplements, 500 mg a day for 16 weeks, improved knee osteoarthritis scores from the starting point, with no placebo group
Randomized single-blind pilot study in 40 people with knee osteoarthritis, comparing bromelain with diclofenac (100 mg a day). After 4 weeks the two did not differ. The 16-week result compares bromelain with each person’s own starting point, not with a control: the total WOMAC score fell from 25.5 to 12.2.
Bromelain supplements, 300 mg three times a day, did not ease muscle soreness after hard arm exercise
Randomized double-blind trial in 40 people, 39 of whom finished, assigned to bromelain, ibuprofen (400 mg three times a day), placebo or no treatment after exercise that strained the elbow flexors. No group differed in pain, range of motion or strength through 96 hours, and ibuprofen did not help either.
In 19 men, bromelain taken by mouth reached the blood as intact enzyme, in small amounts
Study in 19 healthy men who took bromelain, 3 g a day, as a model protein to test whether whole proteins cross the gut wall. Blood levels reached 5,000 pg/mL by 48 hours, about 10.8 micrograms in all, and the enzyme kept at least part of its activity. It did not test any health effect.
Nigerian women who ate pineapple regularly in the third trimester had labor 1.7 hours shorter than women who did not
Retrospective cohort of 2,400 women who delivered in 2018 to 2023, half reporting regular pineapple and half none, using records and questionnaires. Cervical ripening scored 0.8 higher, spontaneous vaginal delivery was more likely (adjusted odds ratio 1.8), and newborn outcomes did not differ. Eating habits were self-reported, and a link does not prove pineapple caused it.
Children with acute sinusitis given a bromelain product had symptoms for 6.66 days, against 7.95 days on standard care
Cohort study of 116 children under 11 at 19 German centers: 62 took the bromelain product alone, 34 took it with standard treatment and 20 had standard treatment only. Bromelain alone recovered fastest, while the combination group took longest (9.06 days). The groups were not randomized, and one child with a known pineapple allergy had a mild reaction.
Mice with colitis fed fresh pineapple juice developed colon neoplasia less often, 35% against 66%, than mice given boiled juice
Study in mice, not people. Mice prone to colitis were given fresh juice with active enzymes or boiled juice with inactive enzymes for up to 6 months. Fresh juice also improved survival and lowered colon inflammation scores.
In rats with a crushed Achilles tendon, fresh pineapple juice lowered a marker of cell damage more than bromelain did
Study in 24 rats, 8 per group, given nothing, oral bromelain (7 mg per kg) or diluted fresh pineapple juice (30 mg per kg) for 14 days. Bromelain raised the number of tendon cells significantly, while the juice did not (p = 0.36). The damage marker was malondialdehyde. This is rodent work.
Bromelain extract slowed the growth of colorectal cancer cells in dishes and in zebrafish and mouse tumor models
Lab study with several colorectal cancer cell lines, a zebrafish model and a mouse xenograft model, using bromelain extract, not the fruit. It triggered reactive oxygen species and cell death pathways. This is cell and animal work and says nothing yet about people who eat pineapple or take bromelain.
Who should be careful with pineapple
Most people can eat pineapple freely. Take a little care if one of these applies:
- Blood thinners and other medicines. Memorial Sloan Kettering advises against bromelain supplements with warfarin or other blood thinners, because lab studies suggest more bruising and bleeding, and notes that bromelain may raise blood levels of tetracycline antibiotics. The fruit holds much less bromelain than a pill, and no study here tested bleeding from eating pineapple. One crossover study found 4 days of pineapple juice raised exposure to celecoxib by 60%, so ask a pharmacist if you take it.
- Pineapple allergy and a sore mouth. Raw pineapple can leave the mouth feeling raw, and bromelain is the likely cause. A true allergy is documented: in a 1979 report, a worker sensitized to bromelain had an asthma attack after eating 190 g of pineapple. Seek medical help for hives, swelling or wheezing.
- Blood sugar. Pineapple had a high glycemic index of 82 in 10 healthy volunteers. If you track blood sugar, check how you respond and keep an eye on portions.
How to choose, store and eat pineapple
- Fresh: the form with active bromelain, so it can tingle in the mouth and stop gelatin from setting. The juice of 1 kg of fruit raised blood melatonin from 48 to 146 pg/mL in 12 men.
- Canned or cooked: heat destroys bromelain, so gelatin sets and the tingle should be milder. The Philippine school trial that found fewer infections used 140 g or 280 g of canned pineapple for 9 weeks.
- Bromelain pills: concentrated extracts, not the fruit, and the form behind the drug warnings above. Trials here used 400 to 900 mg a day, with mixed results.
Pick a firm fruit with no bruises or decay, green crown leaves and a shell turning yellow at the base. It does not ripen after picking, and UC Davis lists 45 to 50°F as best for ripe fruit, with chilling injury below 45°F. Residues are no reason to skip pineapple: in USDA tests of 656 fresh pineapples in 2024, none had a residue above the legal limit.
Sources
- Bromelain. Memorial Sloan Kettering Cancer Center.
- Baur X, Fruhmann G. Allergic reactions, including asthma, to the pineapple protease bromelain following occupational exposure. Clin Allergy. 1979.
- Coffey D. Why does eating pineapple make your mouth tingle? Live Science. 2022.
- Solidifying science: why can certain fruits ruin your gelatin dessert? Scientific American.
- Bromelain. Wikipedia.
- Pineapple. UC Davis Postharvest Research and Extension Center, produce fact sheet.
- Pesticide Data Program annual summary, calendar year 2024. USDA Agricultural Marketing Service.
- Robert SD, Ismail AA, Winn T, Wolever TM. Glycemic index of common Malaysian fruits. Asia Pac J Clin Nutr. 2008.
- Cervo MM, Llido LO, Barrios EB, Panlasigui LN. Effects of canned pineapple consumption on nutritional status, immunomodulation, and physical health of selected school children. J Nutr Metab. 2014.
- Sae-Teaw M, Johns J, Johns NP, Subongkot S. Serum melatonin levels and antioxidant capacities after consumption of pineapple, orange, or banana by healthy male volunteers. J Pineal Res. 2013.
- Helmy SA, El-Bedaiwy HM, El-Masry SM. Effect of pineapple juice on the pharmacokinetics of celecoxib and montelukast in humans. Ther Deliv. 2020.
- Delgarm P, Mokhtare M, Ebrahimi Daryani N, Abolghasemi J, Rahideh ST. Effects of bromelain supplementation on disease activity and quality of life in patients with ulcerative colitis. Sci Rep. 2025.
- Stone MB, Merrick MA, Ingersoll CD, Edwards JE. Preliminary comparison of bromelain and ibuprofen for delayed onset muscle soreness management. Clin J Sport Med. 2002.
History of pineapple
Pineapple began in South America. The wild plant comes from the Paraná and Paraguay river basins, between southern Brazil and Paraguay. Little is known about how it was domesticated, but it spread as a crop across the continent, with evidence of use from 1200 to 800 BC in Peru and from 200 BC to AD 700 in Mexico, where the Maya and Aztecs grew it.
Christopher Columbus was the first European to meet it, on Guadeloupe on November 4, 1493, and the first known illustration appeared in Oviedo’s 1535 history of the Indies. The Tupi-Guarani and Carib peoples called it nanas, a name that spread into many European languages. English took a different route: “pine apple” first meant a pine cone in the 14th century, and John Smith used it for the tropical fruit in 1624. The species name, Ananas comosus, adds “tufted”.
The Portuguese carried pineapple from Brazil to India by 1550. Europe struggled to grow it until the Dutch grower Pieter de la Court developed greenhouse methods near Leiden, and plants reached English gardeners in 1719. A huge “pineapple stove” heated the plants at the Chelsea Physic Garden in 1723. Heated greenhouses were so costly that pineapple became a symbol of wealth, shown off at dinner parties more than eaten.
Hawaii turned it into an industry. James Drummond Dole moved there in 1899 and started a 60-acre plantation in 1900 that grew into the Dole Food Company. In 1911 his employee Henry Ginaca invented an automatic peeling and coring machine, and Hawaii led international trade until the 1960s. Dole closed its Honolulu cannery in 1991, and by 2013 Hawaii grew only about 0.1% of the world’s pineapples.
Today, about 29 million tonnes are grown a year, led by Costa Rica, the Philippines and Indonesia at about 3 million tonnes each. Pineapple is the most economically valuable crop that uses CAM photosynthesis, a water-saving way of taking in carbon dioxide at night, and the second most important tropical fruit, according to a 2015 genome study. Its enzyme has its own history: the Venezuelan chemist Vicente Marcano first isolated bromelain in 1891 by fermenting pineapple fruit.
Sources
- Pineapple. Wikipedia.
- Bromelain. Wikipedia.
- Ming R, VanBuren R, Wai CM, et al. The pineapple genome and the evolution of CAM photosynthesis. Nat Genet. 2015.
Frequently asked questions about pineapple
Is pineapple good for you?
For most people, yes. Per 100 g, fresh pineapple has 50 calories, 1.4 g of fiber and 47.8 mg of vitamin C, 53% of the daily value, and a cup (165 g) gives 88%. Evidence for health effects of the fruit is thin: canned pineapple went with fewer infections in a trial of 98 children, but no study here reaches strong evidence. Most of the research is on bromelain pills.
Why does pineapple make your mouth tingle?
Most likely bromelain, a protein-digesting enzyme in fresh pineapple. It may break down some of the mucus proteins that protect the mouth, and the pineapple’s acidity probably adds to it, but researchers say the effect is not well studied. Heat destroys bromelain, so cooked pineapple should tingle less.
How much pineapple can you eat a day?
No study here sets an ideal amount. The school trial used 140 g or 280 g of canned pineapple for 9 weeks, and one cup of fresh pineapple (165 g) has 83 calories and 16.3 g of sugars. If your mouth gets sore, eat less or switch to cooked or canned pineapple.
Is canned pineapple as healthy as fresh?
The evidence does not rank them. Heat during canning destroys bromelain, but the school trial that found fewer infections used canned pineapple, and the mouse colitis study that favored fresh juice also used boiled juice with inactive enzymes as the control. Check the label, since canned pineapple can be packed in syrup.
Does pineapple help digestion?
It has not been shown. Bromelain breaks down protein, but no trial here tested whether eating pineapple helps digestion. In 70 adults with ulcerative colitis, 400 mg a day of bromelain lowered disease activity scores, but that was a pill and a disease, not everyday digestion. Reviews list flatulence, nausea and headache as side effects of bromelain.
Is pineapple OK for people with diabetes?
It can fit, but it is not a low-sugar fruit. Pineapple had a glycemic index of 82 in 10 healthy volunteers, and 100 g has 9.85 g of sugars and 1.4 g of fiber. A cup (165 g) has 16.3 g of sugars. Portion size and your own readings matter, so check with your care team.
Can eating pineapple bring on labor?
There is no good evidence that it does. The only study here is observational: Nigerian women who reported regular third-trimester pineapple had labor 1.7 hours shorter, but it relied on self-reports and cannot show cause. If you are near term, ask your midwife or doctor before trying it.
Is pineapple good for weight loss?
No study here tested weight loss. Pineapple has 50 calories and 1.4 g of fiber per 100 g, so it is a light snack, but it also has 9.85 g of sugars. Any benefit would come from swapping it for higher-calorie foods, not from bromelain.