Heart Berry – 100% Organic Cranberry Juice 3 L

What Science Says About Cranberry

1. Vitamin C

Raw cranberries carry about 14 mg of vitamin C per 100 g in the USDA reference table, and unsweetened cranberry juice about 9.3 mg per 100 g. [1] [2] A 2025 analysis of fresh fruit found 16.0 mg per 100 g. [3] The wild European small cranberry, Vaccinium oxycoccos, has been reported higher still, at around 31 mg per 100 g. [4] Drying and sweetening removes almost all of it: the same reference table gives sweetened dried cranberries 0.2 mg per 100 g. [2]

2. A-type proanthocyanidins — the compound that made cranberry a research subject

Cranberry proanthocyanidins carry an unusual A-type linkage, and the research question has always been whether they stop bacteria sticking to the cells lining the urinary tract. In a randomised, double-blind crossover study, 32 women took cranberry powder standardised to 18, 36 or 72 mg of proanthocyanidins; urine collected afterwards reduced bacterial adhesion compared with placebo (p<0.001), and at 24 hours only the 72 mg dose still held about 50% of that activity, against 0–12% for the lower doses (p=0.002). [5] A later study in 20 adults found that a juice extract delivering 35.98 mg of soluble proanthocyanidins produced far more urinary anti-adhesion activity than a whole-fruit powder delivering 0.94 mg — mean adjusted area under the curve 94 against 23 (p<0.00001). [6] In one clinical trial, P-fimbriated E. coli was found in 43.5% of the women drinking cranberry juice against 80.0% of those on placebo. [7]

3. Urinary tract infections — what the trials show

The Cochrane review of cranberry products, updated in 2023, pooled 50 randomised trials in 8,857 people. Across 26 trials in 6,211 participants, cranberry reduced symptomatic, culture-verified urinary tract infection, with a risk ratio of 0.70 (95% CI 0.58 to 0.84), rated moderate-certainty evidence. The effect held in women with recurrent infections (RR 0.74, 0.55 to 0.99; 8 trials, 1,555 participants), in children (RR 0.46, 0.32 to 0.68; 5 trials, 504 participants) and in people made susceptible by a urological procedure (RR 0.47, 0.37 to 0.61; 6 trials, 1,434 participants). Juice and syrup as a format gave RR 0.78 (0.62 to 0.97) across 13 trials in 2,831 participants. [8] The largest juice trial gave 373 women 240 ml a day of a 27% cranberry beverage for 24 weeks: clinical infection episodes were 39 against 67, an adjusted incidence rate ratio of 0.61 (0.41 to 0.91, p=0.016) — although culture-positive infections alone did not differ significantly. [9]

4. The dose, and why the numbers disagree

A 2024 meta-analysis of 10 trials in 2,438 participants found an overall risk ratio of 0.85 (0.76 to 0.96, p=0.008), and separated the results by dose: at 36 mg of proanthocyanidins a day or more, RR 0.82 (0.69 to 0.98, p=0.03); below that, no significant effect (p=0.39). [10] That 36 mg benchmark comes from capsules of standardised powder measured by one specific colorimetric method, and it does not transfer between methods. The USDA table, using HPLC, lists 1,201 mg of proanthocyanidins per 100 g of raw cranberries, of which 84% are large polymers, while a butanol-based method on fresh fruit reads 8.3 to 27.9 mg per 100 g. [11] [12] Products are inconsistent too: of 24 cranberry supplements analysed in 2020, one contained 85% less proanthocyanidin than declared and three contained under 15% of the declared amount. [13]

5. Where cranberry did not work

The same Cochrane review found little or no effect in elderly people in institutions (RR 0.93, 0.67 to 1.30; 3 trials, 1,489 participants), in pregnancy (RR 1.06, 0.75 to 1.50; 3 trials, 765 participants) and in people with bladder-emptying problems (RR 0.97, 0.78 to 1.19; 3 trials, 464 participants). [8] A one-year trial in 185 nursing-home women taking 72 mg of proanthocyanidins daily found bacteriuria with pyuria in 29.1% against 29.0% on placebo (odds ratio 1.01, 0.61 to 1.66, p=0.984). [14] And a trial in 319 college women drinking 240 ml of 27% cranberry juice twice a day found recurrence in 20.0% against 14.0% on placebo. [15]

6. Cholesterol ratio and insulin sensitivity

A 2024 meta-analysis of 16 randomised trials in 708 people found cranberry lowered the ratio of total to HDL cholesterol (mean difference −0.24, 95% CI −0.45 to −0.04, p=0.02) and the HOMA-IR measure of insulin resistance (−0.59, −1.05 to −0.14, p=0.01). LDL cholesterol, HDL cholesterol, fasting glucose and HbA1c did not change significantly. [16] An earlier meta-analysis, also of 16 trials, found lower systolic blood pressure and body mass index but no effect on the lipid measures — and noted that cranberry juice specifically was associated with higher triglycerides than other forms. [17]

7. Blood vessels

In a double-blind randomised trial, 45 healthy men took 9 g a day of freeze-dried whole cranberry powder — 525 mg of polyphenols, the equivalent of 100 g of fresh fruit — for one month. Flow-mediated dilation of the brachial artery rose by 1.1% both two hours after a single dose and after a month of daily intake (p≤0.001). [18] In 44 people with coronary artery disease drinking 480 ml a day of a double-strength juice for four weeks, carotid-femoral pulse wave velocity fell from 8.3 to 7.8 m/s while the placebo group rose from 8.0 to 8.4 (p=0.003); blood pressure and brachial artery dilation did not change. [19] A trial in 40 adults with elevated blood pressure drinking 500 ml a day of 27% juice for eight weeks missed its primary endpoint: central systolic pressure was unchanged, with daytime diastolic pressure about 2 mmHg lower (p=0.05). [20]

8. Gut bacteria, and the stomach

Four days of a cranberry extract providing 109 mg of polyphenols a day raised Bifidobacterium and lowered Bacteroides in 39 healthy volunteers. [21] Over 24 weeks, however, a trial in 70 women found no significant change in the overall composition, diversity or function of the gut microbiome. [22] For the stomach, one randomised trial gave 189 adults infected with Helicobacter pylori 500 ml of cranberry juice a day for 90 days; 14 of 97 tested negative on the breath test at day 35, against 5 of 92 on placebo — suppression rather than eradication. [23]

What European regulators have concluded

There is no authorised EU health claim for cranberry in relation to urinary tract health. The European Food Safety Authority has assessed the question four times — in 2009, 2011, 2013 and again in 2025 — and each time concluded that a cause-and-effect relationship had not been established, noting in 2011 that anti-adhesion shown in the laboratory does not establish a clinically relevant effect in the body. [24] [25] [26] The European Medicines Agency takes a separate route: its 2022 herbal monograph recognises pressed cranberry juice as a traditional herbal medicinal product on the basis of long-standing use rather than clinical proof. [27] Both facts are worth holding at once — the trial literature above is real, and it has not been accepted as a claim here.

What has not been studied

The findings above describe the plant and its compounds, drawn from trials of cranberry powders, capsules, extracts and beverages of various strengths. No trial has tested this juice. The proanthocyanidin content of pressed 100% cranberry juice has not been published in the units used to set the 36 mg benchmark, so no serving of any juice can honestly be equated with that dose.

Safety, and who should be careful

In the pooled Cochrane data, gastrointestinal side effects probably do not differ between cranberry and placebo, the commonest being abdominal discomfort. [8] Cranberry has essentially no signal for liver injury: the US LiverTox database rates it an unlikely cause of clinically apparent liver injury and records no convincing case. [28] Three cautions matter. The European Medicines Agency contraindicates cranberry alongside warfarin and tacrolimus, and does not recommend it during pregnancy or breastfeeding or for children and adolescents. [27] It also warns that the oxalate content may raise kidney-stone risk in susceptible people: in a metabolic study, 1 litre of cranberry juice a day for a week raised urinary oxalate from 26.4 to 29.2 mg a day (p=0.04) and urinary calcium from 154 to 177 mg (p=0.0008), while lowering urine pH from 5.97 to 5.67 (p=0.0005) and uric acid from 544 to 442 mg (p<0.0001) — less favourable for calcium-oxalate and uric-acid stones, more favourable for brushite. [29] And cranberry juice is acidic, around pH 2.3 to 2.8, [30] so the ordinary advice for acidic drinks applies: with a meal, rather than sipped through the day.

Scientific References

1. USDA Agricultural Research Service. FoodData Central: Cranberries, raw. FDC ID 171722.
2. USDA Agricultural Research Service. FoodData Central: Cranberry juice, unsweetened, FDC ID 168117; Cranberries, dried, sweetened, FDC ID 171723.
3. Sobrero A, et al. Horticulturae. 2025;11(12):1418. doi:10.3390/horticulturae11121418
4. Snopek L, Jurikova T, Skrovankova S, Mlcek J, Balla S. Molecules. 2019;24(1):24. doi:10.3390/molecules24010024
5. Howell AB, Botto H, Combescure C, et al. Dosage effect on uropathogenic Escherichia coli anti-adhesion activity in urine following consumption of cranberry powder standardized for proanthocyanidin content. BMC Infectious Diseases. 2010;10:94. doi:10.1186/1471-2334-10-94
6. Howell AB, Dreyfus J-F, Chughtai B. Differences in urinary bacterial anti-adhesion activity after intake of cranberry dietary supplements with soluble versus insoluble proanthocyanidins. Journal of Dietary Supplements. 2021. doi:10.1080/19390211.2021.1908480
7. Stapleton AE, Dziura J, Hooton TM, et al. Recurrent urinary tract infection and urinary Escherichia coli in women ingesting cranberry juice daily: a randomized controlled trial. Mayo Clinic Proceedings. 2012;87(2):143–150. doi:10.1016/j.mayocp.2011.10.006
8. Williams G, Stothart CI, Hahn D, Stephens JH, Craig JC, Hodson EM. Cranberries for preventing urinary tract infections. Cochrane Database of Systematic Reviews. 2023, Issue 11, CD001321. doi:10.1002/14651858.CD001321.pub7
9. Maki KC, Kaspar KL, Khoo C, Derrig LH, Schild AL, Gupta K. Consumption of a cranberry juice beverage lowered the number of clinical urinary tract infection episodes in women with a recent history of urinary tract infection. The American Journal of Clinical Nutrition. 2016;103(6):1434–1442. doi:10.3945/ajcn.116.130542
10. Xiong Z, Gao Y, Yuan C, Jian Z, Wei X. Preventive effect of cranberries with high dose of proanthocyanidins on urinary tract infections: a meta-analysis and systematic review. Frontiers in Nutrition. 2024;11:1422121. doi:10.3389/fnut.2024.1422121
11. USDA Agricultural Research Service. Database for the Proanthocyanidin Content of Selected Foods, Release 2.1 (2018). Cranberries, raw.
12. Narwojsz A, Tańska M, Mazur B, Borowska EJ. Fruit physical features, phenolic compounds profile and inhibition activities of cranberry cultivars compared to wild-grown cranberry. Plant Foods for Human Nutrition. 2019;74:300–306. doi:10.1007/s11130-019-00737-7
13. Mannino G, Di Stefano V, Lauria A, Pitonzo R, Gentile C. Vaccinium macrocarpon (cranberry)-based dietary supplements: variation in mass uniformity, proanthocyanidin dosage and anthocyanin profile. Nutrients. 2020;12(4):992. doi:10.3390/nu12040992
14. Juthani-Mehta M, Van Ness PH, Bianco L, et al. Effect of cranberry capsules on bacteriuria plus pyuria among older women in nursing homes: a randomized clinical trial. JAMA. 2016;316(18):1879–1887. doi:10.1001/jama.2016.16141
15. Barbosa-Cesnik C, Brown MB, Buxton M, Zhang L, DeBusscher J, Foxman B. Cranberry juice fails to prevent recurrent urinary tract infection: results from a randomized placebo-controlled trial. Clinical Infectious Diseases. 2011;52(1):23–30. doi:10.1093/cid/ciq073
16. Li X, Chen W, Xia J, Pan D, Sun G. The effects of cranberry consumption on glycemic and lipid profiles in humans: a systematic review and meta-analysis of randomized controlled trials. Nutrients. 2024;16(6):782. doi:10.3390/nu16060782
17. Pourmasoumi M, Hadi A, Najafgholizadeh A, Joukar F, Mansour-Ghanaei F. The effects of cranberry on cardiovascular metabolic risk factors: a systematic review and meta-analysis. Clinical Nutrition. 2020;39(3):774–788. doi:10.1016/j.clnu.2019.04.003
18. Heiss C, Istas G, Feliciano RP, et al. Daily consumption of cranberry improves endothelial function in healthy adults: a double blind randomized controlled trial. Food & Function. 2022;13(7):3812–3824. doi:10.1039/D2FO00080F
19. Dohadwala MM, Holbrook M, Hamburg NM, et al. Effects of cranberry juice consumption on vascular function in patients with coronary artery disease. The American Journal of Clinical Nutrition. 2011;93(5):934–940. doi:10.3945/ajcn.110.004242
20. Richter CK, Skulas-Ray AC, Gaugler TL, Meily S, Petersen KS, Kris-Etherton PM. Effects of cranberry juice supplementation on cardiovascular disease risk factors in adults with elevated blood pressure: a randomized controlled trial. Nutrients. 2021;13(8):2618. doi:10.3390/nu13082618
21. Lessard-Lord J, Roussel C, Lupien-Meilleur J, et al. Short term supplementation with cranberry extract modulates gut microbiota in human and displays a bifidogenic effect. npj Biofilms and Microbiomes. 2024;10:18. doi:10.1038/s41522-024-00493-w
22. Straub TJ, Chou W-C, Manson AL, et al. Limited effects of long-term daily cranberry consumption on the gut microbiome in a placebo-controlled study of women with recurrent urinary tract infections. BMC Microbiology. 2021;21:53. doi:10.1186/s12866-021-02106-4
23. Zhang L, Ma J, Pan K, Go VL, Chen J, You WC. Efficacy of cranberry juice on Helicobacter pylori infection: a double-blind, randomized placebo-controlled trial. Helicobacter. 2005;10(2):139–145.
24. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to proanthocyanidins from cranberry (Vaccinium macrocarpon Aiton) fruit, pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal. 2011;9(6):2215. doi:10.2903/j.efsa.2011.2215
25. EFSA Panel on Dietetic Products, Nutrition and Allergies. Ocean Spray Cranberry Products® and urinary tract infection in women, pursuant to Article 14 of Regulation (EC) No 1924/2006. EFSA Journal. 2009; article 943.
26. Turck D, Bohn T, Cámara M, et al. Pacran®, a powder obtained from cranberries, and defence against bacterial pathogens in the lower urinary tract: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006. EFSA Journal. 2025;23(4):e9319. doi:10.2903/j.efsa.2025.9319
27. European Medicines Agency, Committee on Herbal Medicinal Products. European Union herbal monograph on Vaccinium macrocarpon Aiton, fructus. EMA/HMPC/49135/2017, adopted 23 November 2022.
28. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Cranberry. National Institute of Diabetes and Digestive and Kidney Diseases; NCBI Bookshelf NBK588846, updated 20 January 2023.
29. Gettman MT, Ogan K, Brinkley LJ, Adams-Huet B, Pak CYC, Pearle MS. Effect of cranberry juice consumption on urinary stone risk factors. The Journal of Urology. 2005;174(2):590–594. doi:10.1097/01.ju.0000165168.68054.f8
30. Wu CD, et al. Scientific Reports. 2026;16:28663. doi:10.1038/s41598-026-56025-3; Kato MT, et al. Brazilian Oral Research. 2022;36:e076. doi:10.1590/1807-3107bor-2022.vol36.0076; Dorris MR, Bolling BW. Antioxidants. 2021;10(11):1788. doi:10.3390/antiox10111788