Supplement
Cranberry
Cranberry is taken as juice, tablets, capsules or powder, mainly to prevent repeat urinary tract infections; its proanthocyanidins are thought to stop bacteria sticking to the bladder wall. A Cochrane review found fewer symptomatic, culture-confirmed infections overall, with benefit in women with recurrent infections, children and people having medical procedures, but little or none in older people in care, pregnant women or adults whose bladder does not empty. It has not been shown to treat an infection already under way. Reports and small trials disagree on whether it strengthens warfarin, and some studies found more oxalate in the urine, a kidney stone risk factor.
Sources: PMID 37947276; PMID 38096261; PMID 18516070; PMID 11164137
- Updated
- How we grade
- Best evidence
- Grade B: moderate evidence
What cranberry is good for
How we grade →Moderate evidence
Recurrence Risk: Improves
All 1 outcome ↓
Is cranberry safe?
Safety note. Talk to a doctor or pharmacist before you start cranberry if you take prescription medicines, are pregnant or breastfeeding, or have a long-term health condition. Supplements can interact with medicines.
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
BUrinary Tract Infection
▲ Recurrence Risk1 outcome · 4 studies
Urinary Tract Infection: all the evidence on its own page
| Grade | Outcome | Effect | Size and studies |
|---|---|---|---|
| B | Recurrence RiskSmall ImprovementStudied as: Adult women with repeated urinary tract infections took cranberry by mouth (juice, tablets, capsules or powder) daily for 6 to 12 months, compared with placebo or no treatment; benefit was clearer with tablets, capsules or powder than with juice. The Cochrane review 37947276 rated the evidence for these women moderate certainty.Studies that measured recurrence risk (4 studies)
| Improves | Small effect · 4 studiesReviewed |