Cranberry juice is often given to older people in hospital to prevent urinary tract infection (UTI), although there is little evidence to support its use.
McMurdo, M. E. T., Bissett, L. Y., Price, R. J. G., Phillips, G., & Crombie, I. K. (2005). Does ingestion of cranberry juice reduce symptomatic urinary tract infections in older people in hospital? A double-blind, placebo-controlled trial. Age and Ageing, 34(3), 256-261. https://doi.org/10.1093/ageing/afi101