Cranberry Extract for Recurrent Urinary Tract Infections

February 16, 2015
Jeannette Y. Wick, RPh, MBA, FASCP

Roughly half of all women experience at least 1 urinary tract infection in their lifetime. The problem becomes recurrent for many, so effective non-antibiotic preventive therapies are needed.

Roughly half of all women experience at least 1 urinary tract infection (UTI) in their lifetime. The problem becomes recurrent for many, so effective non-antibiotic preventive therapies are needed.

Cranberries, cranberry juice, and cranberry extracts have a reputation of helping to prevent recurrent UTIs, defined as 2 or 3 experienced within 1 year. However, clinical studies addressing all forms of cranberry have reported mixed results.

A team of researchers looked at the humble berry once again, this time developing a pilot study to evaluate the effects of cranberry extract in patients with recurrent UTIs.

The investigators enrolled 44 patients, half of whom received an oral cranberry extract capsule daily for 2 months alongside lifestyle modification advice on hygiene changes, drinking and voiding times, caffeine reductions, alcohol and spice intake recommendations, and moderate physical activity. The remaining 22 patients comprised the control group and followed lifestyle modification advice alone.

Patients who took cranberry extracts experienced 73.3% fewer UTI episodes during the study period compared with the 2 months prior. In comparison, the control subjects who only followed lifestyle modification advice experienced just 15.4% fewer UTI episodes.

Because UTI symptoms are troublesome for women, measuring symptom reduction is of interest to clinicians. In the cranberry-supplemented group, 7 women were symptom-free, but in the control group, all subjects reported some level of symptoms.

Three subjects (13.6%) in the cranberry group and 8 (36.3%) in the control group required medical consultation for UTI symptoms. Patients who developed UTIs while taking cranberry extracts reported a mean UTI episode duration of 2.5 days, while the control subjects tended to experience longer UTI episodes (3.6±1.7 days).

At the study’s conclusion, urine culture was completely negative in 20 of 22 subjects in the cranberry group (90.9%) and 11 of 22 control subjects (50%). No treatment-related adverse events were observed.

Thus, the researchers reported that use of OTC cranberry extracts supplementation could reduce the need for medical care and antibiotics in women with recurrent UTIs.