Fruit blends, particularly those containing cranberries, blueberries, or other berries, are sometimes marketed as supportive in the prevention or management of urinary tract infections (UTIs). The scientific rationale centers mostly on cranberries, which contain proanthocyanidins believed to inhibit the adhesion of Escherichia coli (E. coli) to the urinary tract epithelium, thereby reducing the likelihood of infection. Several clinical studies and systematic reviews have investigated cranberry products for UTI prevention, with mixed but generally positive results for recurrent UTI prevention, especially in women. However, the effect size is modest, and there is considerable variability in study design, dosage, and product formulation, making definitive recommendations challenging.

Other fruits sometimes included in proprietary blends, like blueberries or pomegranates, have antioxidant and anti-inflammatory properties but significantly less direct evidence supporting their use for UTIs. The use of a general "fruit blend (proprietary)" may dilute the concentration of active compounds such as proanthocyanidins, potentially reducing efficacy compared to standardized cranberry extract.

Overall, while there is some scientific validation—mostly centered on cranberry—for the use of specific fruit components in supporting urinary tract health, evidence for broad "fruit blends" is limited and often extrapolated from cranberry studies. Thus, the scientific evidence is moderate (rated 2/5), and such blends should not be considered a replacement for established preventive or therapeutic UTI measures.