The leaves of uva ursi contain chemicals that have an antimicrobial effect which may potentially could be useful for UTIs. However, patient trials have only focused on acute urinary infections and its usage showed little benefit. There is no evidence as its effectiveness in the treatment of chronic urinary tract infections.
What is uva ursi?
Arctostaphylos uva ursi is a plant species of the genus Arctostaphylos (manzanita). It is commonly referred to as bearberry or bear’s grape. For natural medicinal health purposes, however, only the leaves, not the berries, are used in herbal medicine.
Why is there a link between uva ursi and the treatment of UTI?
- The leaves of uva ursi contains chemicals, primarily hydroquinone and hydroquinone derivatives such as arbutin which has the ability to drain excess water from cells, promoting an antiseptic effect on the kidneys.
- Two studies (i & ii) examined the urine from patients suffering acute UTIs who were given extracts of uva ursi or isolated arbutin. Activity was demonstrated against E. coli, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, and other urinary tract bacteria. It was found that the crude extract of Uva ursi was of more benefit as an antimicrobial than arbutin.
- A study published in the British Medical Journal in 2010 of 309 women found that those recommended to use Uvacin (an OTC preparation including Uva ursi) experienced shorter illness duration, although the numbers who subsequently reported use of the product was low (14% with advice to use versus 1% with no advice).
- A double blind study of 57 women with cystitis published in Current Therapeutic Research in 1993 noted that after one year, the placebo group had 20% incidence of recurrence, whereas the Uva ursi group had no recurrence.The trial patients used a prophylactic extract of UVA-E, containing an aqueous/alcoholic extract of Uva ursi leaves and Taraxacum offinale (dandelion) root.
What are the issues with Uva ursi?
- Controlled trials and studies are often limited in complementary and alternative medicine and involve small numbers of participants. They are often conducted under less rigorous controls, guidelines and environments than those undertaken for the development of new pharmaceutical medications such as antibiotics. Do your research, there should be clear, peer reviewed, empiric evidence as to the efficacy of complementary therapies rather than theorisation about how they may be beneficial in the treatment of a chronic UTI.
- There have been insufficient in-vivo patient trials for the usage of Uva ursi against recurrent urinary tract infections and none for those with embedded or biofilm infections. Studies have focused on those with acute UTI symptoms.
- A trial undertaken by the University of Southampton in the UK published in 2019 recruited 328 patients from primary care settings with acute UTI and compared the results of Uva ursi with a recommendation to take concurrently with Ibuprofen against Uva ursi with no Ibuprofen addition alongside placebo. Trial participants were also provided with back up antibiotics. However the study excluded those patients with frequent recurrent UTI (more than three UTI episodes in the past 12 months). The study co-ordinators found no difference between placebo vs Uva ursi or Ibuprofen vs placebo in terms of symptom severity after 2-4 days. Nearly 57% of participants took back up antibiotics within two weeks of commencement of their UTI. It was also noted that although some symptom reduction was achieved, only the usage of ibuprofen vs placebo reached statistical significance for study purposes and the co-ordinators could not demonstrate superiority of either intervention over placebo in terms of symptom relief or speed of recovery. No participants suffered episodes of upper urinary tract infection during the trial.
- Extremely high doses of Uva ursi, in the range of 10 times greater than the commonly recommended amount, can cause vomiting, ringing in the ears, shortness of breath, convulsions, and collapse in some cases. Liver damage is also a risk with high doses taken over extended periods of time. In a dose of 6,000 mg (6 grams) or higher taken at one time, Uva ursi may cause seizures or cyanosis (a blue tint to the skin caused by a lack of oxygen in the blood). Single doses of 30,000 mg (30 grams) or higher have been reported to cause death.
- Products containing Uva ursi may turn urine green. The plant’s astringent tannin content may cause gastric discomfort. Do not use Uva ursi if suffering from kidney disease.
- Because of a lack of information regarding safety, children, pregnant women, and breast-feeding mothers should not take Uva ursi.
- People with high blood pressure should consult a doctor before using Uva ursi.
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