Cranberry Juice: Nutrients, What Research Shows and Safety

Cranberry juice is pressed from the fruit of the American cranberry, Vaccinium macrocarpon (heath family, Ericaceae). It is tart, so check the label for added sugar. [4] People drink it mostly in the hope of preventing urinary tract infections (UTIs). This page looks at the juice as a drink and keeps it apart from capsules and extracts, which are covered at Cranberry in Herbs & Botanicals. It also says plainly what the research does not show.

Read this first

• Cranberry juice is not a treatment for a UTI. NCCIH says cranberry is not recommended as a treatment for an existing UTI in any population, and that anyone who thinks they have one should see a health care provider. [3] The NHS says there is no evidence cranberry products ease symptoms or treat an infection that has already started. [4]
• For preventing repeat UTIs the evidence is real but uneven. A 2023 Cochrane review (50 trials, 8,857 people) found cranberry products probably reduce UTIs in women with recurrent UTIs and in children. Individual juice trials disagree with each other. [2] [5] [6] [7]
• Warfarin: the NHS says people taking warfarin should avoid cranberry products. [4] NCCIH calls the evidence on an interaction conflicting. [3] Ask the prescriber or pharmacist before changing anything.
• Sugar: the NHS warns that cranberry products can contain a lot of sugar. [4] Even USDA's unsweetened juice has about 30 g of sugars in one cup. [1]
• If you think you have a UTI, see a health care provider for diagnosis and treatment. [3] For trouble breathing or swelling of the face or throat after any food, call 911 (or your local emergency number).

What is in it (USDA values)

The values below are for cranberry juice, unsweetened (USDA FoodData Central item 168117, SR Legacy). [1] The serving column is the USDA household portion of 1 cup, 253 g. [1] Many products on shelves are "cocktails" or blends with added sugar, and USDA's item does not describe those, so check the label.

% Daily Value uses the FDA 2016 Daily Values; values vary with the cranberry variety, how much of the juice is cranberry, and storage. The serving figures are the 100 g values multiplied by 2.53. [1] USDA lists no caffeine and no alcohol in this item. [1]

Plant compounds: NCCIH and Cochrane describe cranberry's proanthocyanidins (PACs), a group of plant polyphenols, as thought to stop certain E. coli bacteria from sticking to the bladder wall. [2] [3] That is a laboratory-based explanation. NCCIH adds that processing into tablets or capsules can lower the PAC content. [3] We did not read a source that measured PACs in typical store-bought juice.

What research says

Who paid for the juice trials was not stated in the abstracts we read, so we do not make any statement about it. The juice trials differed in dose, in how much of the drink was real cranberry juice (one used 27% juice [7]) and in what the placebo was, which is one reason they do not agree. [5] [6] [7]

Eaten as food vs taken as oil, extract or supplement. The juice trials above used drinks. Capsules and tablets were tested too; the Cochrane review says it is unclear whether juice and tablets differ. [2] A result for one product does not carry over to another, because the amount of PACs and sugar differs.

How much is a normal serving

USDA's household portions are 1 cup (253 g) and 1 fluid ounce (31.6 g). [1] That is information, not a prescription. The 2020-2025 Dietary Guidelines for Americans say fruit choices should be "especially whole fruit." [11] For children, the American Academy of Pediatrics (2017) advises no juice in the first year, at most 4 oz a day at ages 1 to 3, 4 to 6 oz at ages 4 to 6, and 8 oz at ages 7 to 18, and prefers whole fruit. [10] The NHS counts unsweetened juice and smoothies together as at most one portion of 5 A DAY, limited to 150 ml a day. [12] WHO recommends keeping free sugars (which include sugars in fruit juices) under 10% of daily energy, with under 5% giving extra benefit. [9] The trials above tested set daily amounts, for example one 240 mL serving a day [5], 4 or 8 oz a day [6], or 8 oz twice a day [7]. That is what the studies tested, not advice.

Safety, allergy and medicines

• Warfarin and other blood thinners: the NHS says to avoid cranberry products on warfarin. [4] NCCIH says the evidence is conflicting. [3] What the studies found: one case report describes a rise in INR (a blood clotting test) after a woman drank about 1.4 to 1.9 liters of cranberry juice cocktail a day for 2 to 4 days. [20] In a small trial of 10 men on stable warfarin, 240 mL of cranberry juice twice daily for a week did not change prothrombin time. [19] Because the sources disagree, ask the prescriber or pharmacist; never change a prescribed medicine on your own. See How interactions work.
• Kidney stones: results are mixed and small. In a controlled diet study, 1 liter of cranberry juice a day for a week raised urine oxalate and calcium and increased the calcium oxalate stone risk score by 18%. [16] In a different crossover trial of 20 men, a diluted juice lowered oxalate and raised citrate in urine. [17] If you have had kidney stones, ask your clinician. NIDDK says drinking enough fluid, mainly water, is the most important step to prevent stones; its page did not mention cranberry. [18]
• Sugar and weight: one cup of unsweetened juice has about 30 g of sugars and 116 kcal. [1] WHO counts sugars in juice as free sugars. [9]
• Unpasteurized juice: the FDA says untreated juice must carry a warning label and that children, older adults, pregnant women and people with weakened immune systems can become seriously ill from it. [21] The FDA does not require a label on juice sold by the glass. [21]
• Pregnancy and breastfeeding: NCCIH says some studies suggest cranberry is safe in amounts found in food, but the evidence is not conclusive for larger amounts; ask a health care provider. [3] The NHS says to speak to a doctor first. [4] See Foods in pregnancy: what official bodies advise.
• Side effects: NCCIH says very large amounts can cause stomach upset and diarrhea, especially in young children. [3] In the Cochrane review, gut side effects probably did not differ from placebo (RR 1.33, 95% CI 1.00 to 1.77). [2]
• Diabetes: the juice carries sugar; ask a clinician or dietitian how it fits a plan.
• Allergy: we did not find a source we read describing a common cranberry allergy. Any food can cause a reaction; for trouble breathing or swelling of the face or throat, call 911. See Food allergy basics and emergency signs.

Choosing, storing and food safety

• Read the front and the label: "100% juice," "juice cocktail" and "juice drink" are not the same, and the NHS says cranberry products can be high in sugar. [4]
• Look for the FDA warning label on refrigerated, untreated juice, and ask staff if juice sold by the glass has been treated. [21]
• We did not read a source on how long opened juice keeps, so check the label directions.

Related pages

• Cranberries and urinary tract infections: what Cochrane found
• Cranberry in Herbs & Botanicals
• Fruit juice vs whole fruit
• Foods and medicine interactions: vitamin K, grapefruit and others
• Foods, kidney disease, potassium and oxalates
• Urinary tract infections and urinary symptoms