Plums: almost everything tested was dried

Prunes beat a fibre supplement at its own job. In the one constipation trial inside a systematic review of four trials too unlike each other to pool, 100 g of prunes a day for 3 weeks gave people with constipation 3.5 complete spontaneous bowel movements a week against 2.8 on 22 g of psyllium. Two of those four trials carried an unclear risk of bias, and the reviewers call the evidence outside constipation weak. In a trial of 120 healthy adults with low fibre intakes, the arm eating 120 g of prunes a day for 4 weeks added 32.8 g of stool a day (95% CI 13.9 to 51.7) compared with water alone, while whole gut transit time did not move. European law attaches its bowel claim to a quantity rather than to the fruit in general. The claim may be printed only on a food supplying 100 g of dried plums a day, roughly 10 to 12 prunes, and the label has to tell the buyer so. Hold on to the word dried. Reviewers of the whole plum literature counted 25 human studies, called 6 of them confirmatory and of moderate quality, and say the trials on dried fruit do not translate to fresh plums on a plate.

The numbers, per 100 g

How much is actually in it

• Even within one USDA entry for uncooked prunes the fibre runs from 5.05 to 7.45 g per 100 g across four samples, a spread of 38%, and iron and manganese spread as far. — USDA Foundation Foods samples of Plums, dried (prunes), uncooked (n = 4 samples) Evidence E source
  Fibre 5.05 to 7.45 g per 100 g (median 6.253, spread 38%), iron 0.658 to 0.921 mg (35%), manganese 0.2445 to 0.364 mg (42%), calcium 38.8 to 50.5 mg (27%)

What a real portion looks like

• The European regulation puts a number on the bowel function claim: it may be used only where a food supplies 100 g of dried plums a day, and the label has to tell the buyer so. — European Union food labelling, conditions of use for the dried plum claim Evidence E source
  Threshold of 100 g of dried plums a day, roughly 10 to 12 prunes, with a mandatory consumer information duty

What cooking and storage change

• Juicing does not throw away what prunes do: in adults with chronic constipation prune juice significantly decreased hard and lumpy stools and increased normal ones, without increasing loose and watery stools. — Japanese adults with chronic constipation in a double blind, randomised, placebo controlled trial of prune juice Evidence B source
  Fewer hard and lumpy stools and more normal stools, with no increase in loose and watery stools
• Drying is what costs plums their vitamin C: the USDA retention table for dried fruit keeps 20% of vitamin C and 50% of folate, while every mineral it lists survives intact. — USDA retention factors for the group Fruits and Fruit Juices, method FRUITS,DRIED Evidence E source
  Vitamin C 20% retained, folate 50% retained, thiamin 70%, riboflavin niacin and vitamin B6 90%, calcium iron magnesium phosphorus potassium sodium zinc and copper 100%

What it does to your health

• Pooled across nine randomised trials, plum supplementation lowered LDL cholesterol by 11.52 mg/dl (95% CI 21.93 to 1.11 lower), and the reduction was also significant in the subgroups using dried plum, in unhealthy participants and in trials longer than 8 weeks. — adults in nine randomised controlled trials of plum supplementation, eleven arms (n = 9 RCTs) Evidence A source
  LDL-c weighted mean difference -11.52 mg/dl (95% CI -21.93 to -1.11), P = 0.03, heterogeneity I2 98.7%
• Across eleven randomised trials, plum supplementation changed body weight by 0.04 kg and systolic blood pressure by 1.24 mmHg, and neither change was distinguishable from zero. — adults in eleven randomised controlled trials of plum supplementation (n = 11 RCTs) Evidence A source
  Body weight WMD 0.04 kg (95% CI -1.55 to 1.63), systolic blood pressure WMD -1.24 mmHg (95% CI -3.08 to 0.59), C-reactive protein WMD 0.23 mg/l (95% CI -0.27 to 0.73)
• In the one constipation trial inside a systematic review of four randomised trials, 100 g of prunes a day for 3 weeks beat 22 g of psyllium on stool frequency, 3.5 against 2.8 complete spontaneous bowel movements a week. — adults in four randomised controlled trials, one in constipation and three in non-constipated people (n = 4 RCTs) Evidence B source
  Stool frequency 3.5 versus 2.8 complete spontaneous bowel movements per week (P = 0.006) and stool consistency 3.2 versus 2.8 on the Bristol scale (P = 0.02) against psyllium
• In 120 healthy adults with low fibre intake, 120 g of prunes a day for 4 weeks added 32.8 g of stool a day compared with water alone, while gut transit time did not move. — 120 healthy adults with low fibre intakes and 3 to 6 stools a week, randomised to 80 g/day prunes, 120 g/day prunes or control for 4 weeks (n = 120) Evidence B source
  Stool weight +22.2 g/day at 80 g/day (95% CI -1 to 45.3) and +32.8 g/day at 120 g/day (95% CI 13.9 to 51.7) versus -0.8 g/day control, P = 0.026; whole gut transit time unchanged
• In three US cohorts followed over 3.5 million person years, three servings of prunes a week carried a hazard ratio for type 2 diabetes of 0.89, and for peaches, plums and apricots 0.97, both intervals touching or crossing 1. — 66,105 women in the Nurses' Health Study, 85,104 women in the Nurses' Health Study II and 36,173 men in the Health Professionals Follow-up Study, free of major chronic disease at baseline (n = 187,382) Evidence C source
  Pooled hazard ratio per three servings a week 0.89 (95% CI 0.79 to 1.01) for prunes and 0.97 (95% CI 0.92 to 1.02) for peaches, plums and apricots; 12,198 incident cases

Safety, limits and interactions

• At 80 to 120 g of prunes a day for 4 weeks in 120 healthy adults, flatulence became significantly more common than on water alone, which is the dose limiting complaint rather than any laboratory harm. — 120 healthy adults with low fibre intakes randomised to 80 g/day or 120 g/day prunes or control water for 4 weeks (n = 120) Evidence B source
  Incidence of flatulence significantly higher on prunes than control; no difference in measured bacteria except a greater rise in Bifidobacteria (P = 0.046)
• In a double blind placebo controlled trial in Japanese adults with chronic constipation, prune juice produced no adverse events and no liver or kidney laboratory abnormalities. — Japanese adults with chronic constipation in a double blind, randomised, placebo controlled trial of prune juice Evidence B source
  No adverse events and no laboratory abnormalities of liver or renal function after prune intake; no increase in flatulence, diarrhoea, loose stools or urgency
• Among birch pollen sensitised patients at a Korean hospital who developed oral allergy syndrome, plum was a trigger in 16.0%, behind apple at 68.0% and peach at 56.0%. — 1,427 patients skin prick tested for inhalant allergens, of whom 125 (8.7%) were sensitised to birch pollen and 20.0% of those developed oral allergy syndrome (n = 125 birch pollen sensitised) Evidence C source
  Plum named as a trigger by 16.0% of oral allergy syndrome patients; 60.0% reacted to three or more foods at once
• Forensic imaging of a decomposed body found a plum pit about 2 cm across lodged in the mouth, the finding that pointed to choking while eating. — one man in his 70s found four days after going missing, examined by postmortem computed tomography and autopsy (n = 1) Evidence D source
  An oval foreign body about 2 cm in the oral cavity, confirmed at autopsy as a pickled plum pit; airway obstruction could not be proven because of decomposition

What people believe that the data does not support

• The European Union allows one health claim for dried plums, that they contribute to normal bowel function, and it is tied to a stated daily amount rather than to the fruit in general. — European Union food labelling, claim on dried plums of prune cultivars Evidence E source
  One authorised claim out of three entries for plums in the register; the other two are non-authorised
• A near identical wording, that prunes can contribute to normal bowel function, was refused in the same European register, so the softer phrasing is the one nobody is allowed to print. — European Union food labelling, claim on prunes Evidence E source
  Non-authorised entry POL-HC-8474 standing beside the authorised POL-HC-8372

Who this works differently for

• In 48 osteopenic women aged 65 to 79, both 50 g and 100 g of dried plum a day for 6 months preserved total body bone mineral density compared with no dried plum. — 48 osteopenic postmenopausal women aged 65 to 79 years, randomised to 50 g/day dried plum, 100 g/day dried plum or control for 6 months (n = 48) Evidence B source
  Total body BMD loss prevented in both dried plum arms versus control, P < 0.05; bone resorption marker TRAP-5b fell by 3 months and stayed down at 6 months
• A 2026 meta-analysis of eleven randomised trials in 747 people found the bone benefit of prunes at the lumbar spine only borderline, with a standardised mean difference of 1.30 whose interval still crosses zero. — 747 participants in eleven randomised controlled trials, effect estimated in postmenopausal women (n = 747) Evidence A source
  Lumbar spine BMD standardised mean difference 1.30 (95% CI -0.03 to 2.63), heterogeneity I2 98%; no significant difference at other BMD sites and none in bone turnover markers
• In 183 postmenopausal women who completed a 12 month trial, 50 g or 100 g of prunes a day left blood glucose and lipid markers unchanged, while android fat rose 3.19% in the control group and fell 0.02% on 100 g. — 183 postmenopausal women, mean age 62.1 years, allocated to no prune control, 50 g/day prune or 100 g/day prune for 12 months (n = 183) Evidence B source
  No change in glycemic control or blood lipids at 12 months (all P > 0.05); android total mass +3.19% (SD 5.5) in control versus -0.02% (SD 5.6) on 100 g/day, P < 0.01
• Across pooled surveys of metal levels in fruit, plum carried the highest copper concentration of the fruits compared, yet the calculated non-carcinogenic hazard quotient stayed below 1 even for infants. — fresh and processed fruits sampled in surveys from several WHO regions, with hazard quotients modelled for infants and adults Evidence C source
  Plum ranked highest and banana lowest for copper; total target hazard quotient below 1 in infants

What is still unknown

• The only systematic review of plums as a whole food counted 25 human studies and found just 6 of them confirmatory and of moderate quality, the rest exploratory. — 73 peer reviewed articles on Prunus domestica and Prunus salicina, of which 25 were human studies (n = 73 articles, 25 human studies) Evidence C source
  6 confirmatory studies of moderate quality against 19 exploratory ones
• Almost everything known about plums in people was measured on the dried fruit, so the reviewers warn that the findings do not translate to fresh plums on a plate. — human trials included in a systematic review of Prunus domestica and Prunus salicina (n = 25 human studies) Evidence C source
  Most human trials used dried plums rather than fresh fruit, which the authors name as a limit on dietary advice

The bottom line

Blood numbers move less than the gut does. Across nine randomised trials LDL cholesterol fell by 11.52 mg/dl (95% CI 21.93 to 1.11 lower), an average taken from trials so unlike each other that heterogeneity reached 98.7%. The reduction was also significant in the subgroups using dried plum, in participants who were already unwell and in trials running longer than 8 weeks. Eleven trials of the same kind put body weight 0.04 kg apart (95% CI -1.55 to 1.63) and systolic pressure 1.24 mmHg apart (95% CI -3.08 to 0.59), and neither change was distinguishable from zero. In 183 postmenopausal women followed for a full year, 50 g or 100 g of prunes a day left glucose and lipid markers unchanged. Bone has the longest trials. In 48 osteopenic postmenopausal women aged 65 to 79, sixteen per arm, both 50 g and 100 g a day for 6 months held total body bone density where the control group lost it. A 2026 meta-analysis of eleven trials in 747 people put the lumbar spine effect at a standardised mean difference of 1.30 with an interval from -0.03 to 2.63 that still crosses zero, at 98% heterogeneity, which is why its authors call the finding borderline. Diabetes data is observational only: in three US cohorts reporting their food on questionnaires, three servings of prunes a week carried a hazard ratio of 0.89 (95% CI 0.79 to 1.01), and plums pooled with peaches and apricots 0.97 (95% CI 0.92 to 1.02). Drying changes the food. The USDA retention table for dried fruit keeps 20% of vitamin C and 50% of folate while every mineral it lists survives whole, and those factors are set for the food group and the drying method rather than for plums by name. Even a table figure is approximate here. Four USDA samples of uncooked prunes ran from 5.05 to 7.45 g of fibre per 100 g, a spread of 38%, with iron and manganese as wide. Juicing keeps the effect: in Japanese adults with chronic constipation, prune juice cut hard and lumpy stools without producing loose or watery ones, though that abstract gives no sample size or effect size. Tolerance is the limit people actually meet. At 80 to 120 g a day for 4 weeks those 120 healthy adults reported flatulence more often than the water group, in symptom diaries rather than a blinded adverse event system. The prune juice trial found no adverse events and no liver or kidney abnormalities. Raw plum is a birch pollen food. Among 125 birch sensitised patients at one Korean hospital, plum was named as a trigger of oral allergy syndrome by 16.0% of those who had it, behind apple at 68.0% and peach at 56.0%. Plum carried the highest copper of the fruits in pooled contamination surveys, where local soil drives the numbers, and the modelled hazard quotient stayed below 1 even for infants. The stone is a separate hazard: one forensic case describes a man in his 70s found with a 2 cm pickled plum pit in his mouth, where decomposition prevented proof that it blocked the airway. We found no trials of plums in pregnancy and none on interactions with medicines.

Sources

1. plums-r4-19 · USDA FoodData Central Foundation Foods, dataset
   Plums, dried (prunes), uncooked: Fiber, total dietary 6.251 G, range 5.05-7.45 (median 6.253), 4 samples, spread 38%; Iron, Fe 0.7474 MG, range 0.658-0.921, spread 35%; Manganese, Mn 0.2831 MG, range 0.2445-0.364, spread 42%; Calcium, Ca 44.05 MG, range 38.8-50.5, spread 27%
   USDA FoodData Central, Foundation Foods, release 2026-04-30 · checked 2026-09-24
2. plums-r4-16 · regulation, conditions of use of an authorised claim
   The claim may be used only for food which provides a daily intake of 100 g of dried plums (prunes). In order to bear the claim, information shall be given to the consumer that the beneficial effect is obtained with a daily intake of 100 g of dried plums (prunes).
   Commission Regulation (EU) No 432/2012, consolidated text 01.01.2016 · checked 2026-09-24
3. plums-r4-17 · double-blind randomised placebo-controlled trial in humans
   Prune intake significantly decreased hard and lumpy stools while increasing normal stool and not increasing loose and watery stools.
   Am J Gastroenterol, 2022 · checked 2026-09-24
4. plums-r4-18 · USDA Table of Nutrient Retention Factors, dataset
   USDA-RETN-R6:158 FRUITS,DRIED, group Fruits and Fruit Juices: vitamin_c_mg 20% retained, folate_total_ug 50%, thiamin_mg 70%, riboflavin_mg 90%, niacin_mg 90%, vitamin_b6_mg 90%, calcium_mg 100%, iron_mg 100%, magnesium_mg 100%, phosphorus_mg 100%, potassium_mg 100%, sodium_mg 100%, zinc_mg 100%, copper_mg 100%
   USDA Table of Nutrient Retention Factors, Release 6, 2007, Retn_Code 158 · checked 2026-09-24
5. plums-r4-01 · systematic review and meta-analysis of RCTs
   plum supplementation reduces the LDL-c levels in the pooled sample (WMD = -11⋅52 mg/dl; 95 % CI -21⋅93, -1⋅11, P = 0⋅03...and also in some of the subgroups of individuals (dried plum, unhealthy subjects, duration more than 8 weeks)
   J Nutr Sci, 2023 · checked 2026-09-24
6. plums-r4-02 · systematic review and meta-analysis of RCTs
   we were unable to detect any significant impact of plum supplementation on body weight (weight mean difference (WMD) of 0.04 kg; 95% CI: -1.55, 1.63, p = 0.959)...systolic blood pressure (WMD -1.24 mmHg; 95% CI: -3.08, 0.59, p = 0.185)
   Clin Nutr ESPEN, 2022 · checked 2026-09-24
7. plums-r4-05 · systematic review of RCTs in humans
   In constipation, 3 weeks of prune consumption (100 g/day) improved stool frequency (3.5 vs. 2.8 CSBM per week, P = 0.006) and stool consistency (3.2 vs. 2.8 on Bristol stool form scale, P = 0.02) compared with psyllium (22 g/day).
   Aliment Pharmacol Ther, 2014 · checked 2026-09-24
8. plums-r4-06 · parallel group randomised controlled trial in humans
   There were significantly greater increases in stool weight in both the 80 g/d (mean + 22.2 g/d, 95% CI -1-45.3) and 120 g/d (+32.8 g/d, 95% CI 13.9-51.7) prune groups compared with control (-0.8 g/d, 95% CI -17.2 to 15.6, P = 0.026).
   Clin Nutr, 2019 · checked 2026-09-24
9. plums-r4-07 · prospective cohort studies, pooled
   the pooled hazard ratios of type 2 diabetes for every three servings/week were 0.74 (0.66 to 0.83) for blueberries...0.89 (0.79 to 1.01) for prunes...0.97 (0.92 to 1.02) for peaches, plums, and apricots
   BMJ, 2013 · checked 2026-09-24
10. plums-r4-09 · parallel group randomised controlled trial in humans
    The incidence of flatulence was significantly higher after prune consumption.
    Clin Nutr, 2019 · checked 2026-09-24
11. plums-r4-10 · double-blind randomised placebo-controlled trial in humans
    There were no adverse events or laboratory abnormalities of liver or renal function after prune intake.
    Am J Gastroenterol, 2022 · checked 2026-09-24
12. plums-r4-11 · retrospective chart review in humans
    Apple (68.0%), peach (56.0%), nuts (36.0%), kiwi (20.0%), persimmon (20.0%), plum (16.0%), and cherry (16.0%) were frequent triggers
    J Korean Med Sci, 2018 · checked 2026-09-24
13. plums-r4-13 · forensic case report
    Autopsy confirmed this as the pit of a pickled plum (umeboshi), retrieved from a cluster of maggots...the cause of death involved food aspiration-related choking
    Leg Med (Tokyo), 2026 · checked 2026-09-24
14. plums-r4-14 · regulatory register entry
    POL-HC-8372 Dried plums of 'prune' cultivars (Prunus domestica L.) Dried plums/prunes contribute to normal bowel function Authorised
    EU Register on nutrition and health claims, claim POL-HC-8372, snapshot 2026-09-21 · checked 2026-09-24
15. plums-r4-15 · regulatory register entry
    POL-HC-8474 Prunes Dried plums/prunes can contribute to normal bowel function -/- Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-8474, snapshot 2026-09-21 · checked 2026-09-24
16. plums-r4-03 · randomised controlled trial in humans
    Both doses of dried plum were able to prevent the loss of total body BMD compared with that of the control group (P < 0.05).
    Osteoporos Int, 2016 · checked 2026-09-24
17. plums-r4-04 · systematic review and three-level mixed-effects meta-analysis of RCTs
    The effect of prune intervention in postmenopausal women was borderline significant at the lumbar spine, with BMD slightly higher in the intervention group (SMD [95% CI] = 1.30 [-0.03, 2.63]
    Nutrients, 2026 · checked 2026-09-24
18. plums-r4-08 · 12-month parallel design randomised controlled trial in humans
    Prune supplementation at 50 g/d or 100 g/d did not alter markers of glycemic control and blood lipids after 12 mo compared with the control group (all P > 0.05).
    J Nutr, 2024 · checked 2026-09-24
19. plums-r4-12 · meta-analysis of cross-sectional contamination surveys
    Moreover, the highest and lowest concentrations of Cu were related to plum and banana, respectively...the calculated TTHQ level in infants was below 1
    Biol Trace Elem Res, 2023 · checked 2026-09-24
20. plums-r4-20 · systematic review across in vitro, animal and clinical studies
    The level of evidence remains low. Of the 25 human studies, 6 were confirmatory studies of moderate quality, while 19 were exploratory.
    Phytother Res, 2016 · checked 2026-09-24
21. plums-r4-21 · systematic review across in vitro, animal and clinical studies
    Most of the human trials used the dried version of plums rather than fresh fruit, thus limiting translation to dietary messages of the positioning of plums in a healthy diet.
    Phytother Res, 2016 · checked 2026-09-24