Pineapple, bromelain and the dose on the label

The enzyme is the reason people look pineapple up, and every trial of it used a capsule. After skin cancer surgery, 1500 mg a day of a concentrated bromelain preparation for fifteen days got stitches out 2.6 days sooner than standard care in sixty patients, in a single-blind trial with no placebo. The seven randomised trials behind bromelain as an anti-inflammatory used doses from 99.9 to 1200 mg a day, mostly inside mixtures, and measured blood markers rather than how anyone felt. Nobody has measured how much active bromelain survives from a slice of fruit, so the distance between those trials and a fruit bowl is not something you close by eating more pineapple. The one use of this fruit that hospitals measure is the juice you drink before a scan: its manganese suppresses the signal from fluid in the gut, and the bile ducts come out clearer.

The numbers, per 100 g

What your body absorbs

• Adding a vitamin C rich fruit to a meal moved three markers of iron status and left absorption itself unchanged. — 15 randomised trials with 1381 participants, 806 in intervention and 575 in control, females aged 15 to 74 and children (n = 1381) Evidence A source
  Serum ferritin rose 9.39 µg/L (7 trials, n = 762, P < 0.001, moderate certainty), haemoglobin 1.34 g/L (12 trials, n = 1141, P = 0.01, moderate certainty), serum transferrin receptor fell 0.37 mg/L (6 studies, P < 0.001, high certainty), while iron absorption itself showed no effect (3 studies, MD 3.36%, P = 0.07, low certainty) and plasma ferritin did not move (4 studies, high certainty)

What it does to your health

• Hospitals give patients pineapple juice to drink before a scan, and it makes the bile ducts easier to see. — 16 studies with 1360 participants, eight on magnetic resonance cholangiopancreatography and eight on magnetic resonance enterography (n = 1360) Evidence A source
  Against non-contrast scanning, pineapple juice gave pooled mean differences of 1.04 for bile duct visibility (95% CI 0.23 to 1.84) and 0.95 for pancreatic duct visibility (0.04 to 1.85), and a combined odds ratio of 5.01 (2.34 to 10.64, p < 0.0001) for pancreaticobiliary duct visibility; against synthetic agents the odds of an excellent enterography image were lower at 0.36 (0.18 to 0.73)

Safety, limits and interactions

• Pineapple topped the fruit list for one toxic metal and sat at the bottom for another, and neither mattered to the risk total. — published measurements of arsenic, lead, cadmium, copper, nickel and iron across fresh and processed fruits worldwide Evidence C source
  The highest concentrations of arsenic, cadmium and lead were found in pineapple, mango and cherry respectively, while the lowest of those metals were in berries, pineapple and berries; total target hazard quotient in infants stayed below 1, and the review concludes that eating fresh and processed fruit is safe

What people believe that the data does not support

• The whole case for pineapple enzyme as an anti-inflammatory rests on seven randomised trials. — 1375 records retrieved, 7 randomised controlled trials eligible (n = 7 trials) Evidence C source
  Most studies reported reduced inflammatory parameters, with two of the combined-therapy studies and two of the bromelain-alone studies showing reductions; doses in combined studies ranged from 99.9 to 1200 mg a day over 3 to 16 weeks; the markers measured included IL-6, IL-8, TNF-α, IL-1β, IL-10, CRP and others
• Four health claims naming pineapple have been filed in Europe and none was allowed. — — Evidence E source
  All four register entries naming pineapple carry the status Non-authorised; the quoted one asked to recommend pineapple powder and a bromelain-standardised extract during a slimming diet on the grounds that bromelain has anti-oedematous activity and can help drain tissues with cellulitis

Who this works differently for

• A surgical trial of pineapple enzyme would not enrol anyone taking warfarin. — 60 patients with non-melanoma skin cancer of the head and neck (n = 60) Evidence E source
  Patients on warfarin were excluded because of a possible contraindication with bromelain, as were those with allergy to pineapple, uncontrolled diabetes, malnutrition, immunosuppression, corticosteroid regimens, radiotherapy or active infection

What is still unknown

• Fifteen hundred milligrams of the enzyme a day after skin surgery got stitches out two and a half days sooner. — 60 patients with non-melanoma skin cancer after Mohs micrographic surgery and flap reconstruction, mean age 69.2 years, 71.7% male (n = 60) Evidence B source
  Time to suture removal was 2.6 days shorter with bromelain (95% CI 0.74 to 4.11, p = 0.006); the early wound healing score was better at day 7 (7.2 against 5, p < 0.001) and day 14 (8.56 against 7.3, p = 0.014); pain, inflammation and cosmetic satisfaction showed non-significant trends and no major complications occurred

The bottom line

Pineapple carries about 58 mg of vitamin C per 100 g, and that number belongs to the raw fruit. Across our ten USDA entries the same figure runs from 7.3 to 58.61 mg, because canned and dried pineapple lose most of it, and eight of the ten rows in the table above are canned or frozen. If your pineapple comes out of a tin in syrup, the 58 is not yours. A meta-analysis of fifteen trials on 1381 people found that adding a vitamin C rich fruit to meals raised serum ferritin and haemoglobin and lowered serum transferrin receptor. The direct measure of iron absorption itself did not move, on three small studies the reviewers rated low certainty. Those trials used whatever ascorbate-rich fruit they chose, so none of this is a trial of pineapple. Read it as a reason to put fruit beside a plate of beans if you are short of iron. Two other things deserve a minute. A worldwide review of toxic metals in fruit found pineapple highest for arsenic and lowest for cadmium in the same sentence. That says more about where each sample grew than about the fruit. The review's own risk calculation for infants stayed below the level that would matter. Two things the surgical trial above refused to enrol are worth naming out loud. One is allergy to pineapple. Some people are allergic to this fruit, which is why the investigators screened for it, and it is the only allergen that appears anywhere in what we hold on pineapple. The burning or tingling some people report from fresh pineapple is a separate thing, and nobody in the literature we hold has measured it, so we cannot tell you where one ends and the other begins. The other is warfarin. That trial refused anyone taking it, because the investigators were unwilling to risk a bromelain interaction. No event was measured and no interaction was demonstrated. If you take an anticoagulant and are thinking about a bromelain supplement, that is a question for the prescriber, and a slice of pineapple is a different question. Europe has been asked four times to approve a health claim naming pineapple, including one about draining tissue during a slimming diet, and refused all four. A refusal records that a dossier failed to convince assessors, which is not the same as showing the fruit does nothing.

Sources

1. pin-r5-01 · systematic review and meta-analysis of interventions
   Including ascorbate-rich fruits in meals had a positive impact on serum ferritin [7 trials, n = 762; mean difference (MD) = 9.39 μg/L; P < 0.001; moderate certainty], hemoglobin (12 trials, n = 1141; MD = 1.34 g/L; P = 0.01; moderate certainty), serum transferrin receptor (6 studies; MD = -0.37 mg/L; P < 0.001; high certainty), and iron balance (1 trial; MD = 2.4; low certainty).
   Am J Clin Nutr, 2026 · checked 2026-09-22
2. pin-r5-02 · systematic review and meta-analysis
   Compared to non-contrast MRCP, MRCP with pineapple juice showed improved pancreaticobiliary duct visibility (Combined odds ratio, 5.01; 95 % CI: 2.34, 10.64; p < 0.0001).
   Eur J Radiol, 2026 · checked 2026-09-22
3. pin-r5-03 · systematic review, meta-analysis and health risk assessment
   According to findings highest concentrations of As, Cd and Pb were observed in pineapple, mango, and cherry, while the lowest concentrations of these metals were found in berries, pineapple, and berries.
   Biol Trace Elem Res, 2023 · checked 2026-09-22
4. pin-r5-04 · systematic review of clinical trials
   Seven (7) randomized controlled trials were eligible for the systematic review.
   Clin Nutr ESPEN, 2023 · checked 2026-09-22
5. pin-r5-07 · regulatory register entry
   POL-HC-6600 Ananas : Pineapple powder (Ananas sativus) obtained from fruit juice and stems AND Dry aqueous extract of pineapple standardized at 2% of bromelain Recommended during slimming diet, at the same time of dietary measures. Pineapple is a tropical plant whose stems contain bromelain, a proteolytic enzymatic complex. Bromelain is a proteolytic enzyme with anti-edematous activity which can help to drain tissues with cellulitis. Non-authorised
   EU Register on nutrition and health claims, claim POL-HC-6600, snapshot of 2026-09-21 · checked 2026-09-22
6. pin-r5-05 · stated exclusion criterion within a randomised controlled trial
   Patients with any disturbing factor to wound healing (i.e., uncontrolled diabetes, malnutrition, immunosuppression, corticosteroid regimens, and radiotherapy), allergy to pineapple, any other diagnosis rather than SCC or BCC, active infections, and warfarin administration (due to possible contraindication with bromelain) were excluded from the study.
   BMC Surg, 2026 · checked 2026-09-22
7. pin-r5-06 · randomised controlled trial
   Bromelain significantly shortened time to suture removal compared with controls (2.6 days, 95% CI: 0.74-4.11; p = 0.006).
   BMC Surg, 2026 · checked 2026-09-22