Cranberry supplements: a promising yet controversial aid in preventing UTIs

This systematic review and meta-analysis explore the controversial role of cranberry (Vaccinium spp.) as an adjuvant therapy for preventing urinary tract infections (UTIs) in susceptible populations. UTIs are among the most common bacterial infections, affecting approximately 150 million people globally each year and causing significant morbidity. This analysis included 23 trials with 3979 participants to assess the impact of cranberry-based products on UTI recurrence. The results demonstrated that cranberry supplementation significantly reduces the incidence of UTIs in high-risk groups. Specifically, the meta-analysis found a relative risk reduction of 32%, with notable benefits observed in women with recurrent UTIs (RR = 0.68), children (RR = 0.55), and patients with indwelling catheters (RR = 0.49). Moreover, cranberry juice proved to be more effective than capsules or tablets, achieving a relative risk reduction of 35% compared to other forms.
However, despite these promising results, the overall quality of evidence remains low, necessitating cautious interpretation. The review highlighted that while cranberry products can be beneficial, their effectiveness varies across different populations, with less pronounced effects in elderly patients, pregnant women, and those with neuropathic bladder. The study calls for further high-quality research to confirm these findings and determine the optimal dosage and form of cranberry supplements. In conclusion, cranberry supplements appear to offer a significant benefit in preventing recurrent UTIs in specific high-risk groups, though their generalizability and long-term efficacy need further investigation.