NutriDex

The Supplement Research Compendium
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Cranberry

Vaccinium macrocarpon

Tart berry studied for urinary tract health

Moderate evidence 🍎Fruits

✚ Updated · How we grade evidence

Evidence tier
Moderate
Research weight
Citations
8 verified / 8
Classification
Fruits
❝
What the evidence says. Several controlled trials; effects real but modest or context-dependent.

Nutrition per serving 1 cup whole (100 g)

100gSERVING
  • Water 87.3 g87%
  • Sugars 4.3 g4%
  • Fibre 3.6 g4%
  • Other carbs 4.1 g4%
  • Protein 0.5 g0%
  • Fat 0.1 g0%
What's in one serving, by weight — average composition (USDA).
Vitamin C16%Fibre13%Manganese12%Vitamin E9%Copper6%Vitamin K4%
One serving as % of the adult daily requirement (FDA Daily Values). The bold outer ring = 100% of a day's needs.
46 kcal0.46 g protein3.6 g fiber0.13 g fat
NutrientPer serving% daily value
Vitamin C14 mg16%
Fibre3.6 g13%
Manganese0.27 mg12%
Vitamin E1.3 mg9%
Copper0.06 mg6%
Vitamin K5 mcg4%
Potassium80 mg2%

Composition data: USDA FoodData Central ↗

What is Cranberry?

Cranberry (Vaccinium macrocarpon) is a fruit used for reduces risk of recurrent urinary tract infections in susceptible groups (women with recurrent utis, children). NutriDex grades the human evidence as Moderate. The strongest human evidence is for prevention of recurrent urinary tract infections: a 2023 Cochrane review of 50 studies (8,857 participants; 45 placebo-controlled RCTs) found cranberry products reduce the risk of symptomatic, culture-verified UTIs in women with recurrent infections, in children, and in other susceptible people (overall RR about 0.70), with proanthocyanidins thought to block E. coli adhesion; no benefit was seen in the elderly, those with bladder-emptying problems, or pregnant women. A dose-response meta-analysis suggests the effect concentrates at intakes of about 36 mg proanthocyanidins per day or more (roughly 18% risk reduction). Cardiometabolic data are weaker and inconsistent: meta-analyses report a modest reduction in systolic blood pressure and BMI but no reliable change in lipids, glucose, or inflammatory markers. Most positive trials use juice or concentrated supplements rather than whole fruit, and quality is often limited by small samples, heterogeneity, and industry funding. Whole raw cranberries are nutrient-dense and low in sugar but are too tart to eat in large quantities, so real-world intake usually comes from sweetened products that add sugar.

Purported Benefits

✓Reduces risk of recurrent urinary tract infections in susceptible groups (women with recurrent UTIs, children)
✓Proanthocyanidins inhibit E. coli adhesion to the bladder wall
✓May modestly lower systolic blood pressure (inconsistent evidence)
✓Rich source of vitamin C and antioxidant polyphenols
✓Possible inhibition of H. pylori and oral-bacteria adhesion
✓Low sugar relative to most fruits

Dosing & Compounds

Typical Dose
A standard culinary serving is about 1 cup (100 g) of fresh raw berries. For UTI prevention, trials use cranberry juice or capsules; benefit is most consistent at doses delivering roughly 36 mg or more of proanthocyanidins per day, taken continuously for several weeks to months.
Active Compounds
A-type proanthocyanidins (condensed tannins)Anthocyanins (cyanidin & peonidin glycosides)Quercetin and other flavonolsVitamin C (ascorbic acid)Organic acids (quinic, malic, citric)Vitamin E (tocopherols)ManganesePectin (soluble fibre)Ursolic acid (triterpenoid)

Safety & Cautions

Generally safe as a food. Cranberry juice and concentrated extracts may potentiate warfarin and increase bleeding/INR in some reports, so anticoagulant users should be cautious. Cranberries are high in oxalate and may raise kidney-stone risk in predisposed individuals at high intakes. Commercial cranberry juices and dried cranberries are often heavily sweetened, adding significant sugar and calories. Acidic juice can aggravate reflux; rare allergy is possible. Educational only — always check with your doctor or pharmacist before combining Cranberry with any medicine.

Key Studies

Systematic review / Meta-analysis Williams 2023 ✓ Full text
Cochrane review of 50 studies (8,857 participants; 45 placebo-controlled RCTs): cranberry products reduce risk of symptomatic, culture-verified UTIs in women with recurrent UTIs, children, and other susceptible people (overall RR ~0.70); no benefit in the elderly, those with bladder-emptying problems, or pregnant women.
Meta-analysis Xiong 2024 ✓ PubMed
Meta-analysis of 10 RCTs: at proanthocyanidin intakes of 36 mg/day or more, cranberry reduced UTI risk by 18% (RR 0.82); no significant reduction at lower doses, supporting a dose threshold.
Meta-analysis European Urology Focus 2024 (Network meta-analysis) ✓ PubMed
Systematic review and network meta-analysis of 20 trials (3,091 participants) found cranberry juice associated with a 54% lower rate of UTIs and 49% lower antibiotic use versus placebo liquid.
Meta-analysis Frontiers in Nutrition 2024 ✓ Source
Meta-analysis/systematic review found cranberries with high proanthocyanidin dose significantly reduced UTI risk, with benefit most evident when product use duration was between 12 and 24 weeks.
Meta-analysis Pourmasoumi 2020 ✓ PubMed
Meta-analysis of RCTs: cranberry significantly reduced systolic blood pressure and BMI, with no reliable effect on lipids, glucose, or CRP.
Systematic review / Meta-analysis Jepson 2012 ✓ PubMed
Earlier Cochrane review concluded cranberry juice was less effective than previously suggested for preventing UTIs, highlighting evidence limitations and high dropout.
RCT Hormoznejad 2020 ✓ PubMed
Double-blind placebo-controlled RCT in NAFLD: cranberry extract plus a weight-loss diet produced greater reductions in ALT and insulin/insulin resistance than diet alone.
RCT Novotny 2015 ✓ PubMed
RCT: 8 weeks of low-calorie cranberry juice lowered diastolic BP, CRP, triglycerides and fasting glucose versus placebo in adults with elevated baseline values.
8 sources cited · 8 verified Search all studies on PubMed ↗

Common questions about Cranberry

What is Cranberry used for?

Cranberry is most often taken for Reduces risk of recurrent urinary tract infections in susceptible groups (women with recurrent UTIs, children), Proanthocyanidins inhibit E. coli adhesion to the bladder wall, May modestly lower systolic blood pressure (inconsistent evidence), Rich source of vitamin C and antioxidant polyphenols. Tart berry studied for urinary tract health

Does Cranberry work — what does the evidence say?

Moderate evidence. Several controlled trials; effects real but modest or context-dependent. The strongest human evidence is for prevention of recurrent urinary tract infections: a 2023 Cochrane review of 50 studies (8,857 participants; 45 placebo-controlled RCTs) found cranberry products reduce the risk of symptomatic, culture-verified UTIs in women with recurrent infections, in children, and in other susceptible people (overall RR about 0.70), with proanthocyanidins thought to block E. coli adhesion; no benefit was seen in the elderly, those with bladder-emptying problems, or pregnant women. A dose-response meta-analysis suggests the effect concentrates at intakes of about 36 mg proanthocyanidins per day or more (roughly 18% risk reduction). Cardiometabolic data are weaker and inconsistent: meta-analyses report a modest reduction in systolic blood pressure and BMI but no reliable change in lipids, glucose, or inflammatory markers. Most positive trials use juice or concentrated supplements rather than whole fruit, and quality is often limited by small samples, heterogeneity, and industry funding. Whole raw cranberries are nutrient-dense and low in sugar but are too tart to eat in large quantities, so real-world intake usually comes from sweetened products that add sugar.

What is the typical dose of Cranberry?

A standard culinary serving is about 1 cup (100 g) of fresh raw berries. For UTI prevention, trials use cranberry juice or capsules; benefit is most consistent at doses delivering roughly 36 mg or more of proanthocyanidins per day, taken continuously for several weeks to months.

Is Cranberry safe? Any cautions or side effects?

Generally safe as a food. Cranberry juice and concentrated extracts may potentiate warfarin and increase bleeding/INR in some reports, so anticoagulant users should be cautious. Cranberries are high in oxalate and may raise kidney-stone risk in predisposed individuals at high intakes. Commercial cranberry juices and dried cranberries are often heavily sweetened, adding significant sugar and calories. Acidic juice can aggravate reflux; rare allergy is possible.

How many studies support Cranberry?

NutriDex cites 8 sources for Cranberry, graded "Moderate".

Cite this page
APA

Peh, D. (2026). Cranberry (Vaccinium macrocarpon): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 26 Jun 2026, from https://nutridex.info/s/cranberry

BibTeX
@misc{nutridex_cranberry,
  author       = {Peh, Daryl},
  title        = {Cranberry (Vaccinium macrocarpon): Benefits, Dosage, Side Effects \& Evidence},
  year         = {2026},
  howpublished = {NutriDex --- The Supplement Research Compendium},
  url          = {https://nutridex.info/s/cranberry},
  note         = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-06-26}
}

For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.

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