Cranberries (and blueberries!) contain a chemical that helps prevent bacteria that cause urinary tract infections from adhering to your system. Cranberries also contain Vitamin C, and this makes your urine more acidic and a more hostile environment for bacteria.
Existing research on whether drinking cranberry juice helps prevent UTIs suggest that drinking cranberry juice may be an effective way of preventing UTIs, especially if you get UTIs frequently:
*Individuals who drink two glasses of unsweetened cranberry juice daily were 86% as likely to get a UTI than people who just drink 2-3 cups of water instead of cranberry juice
*Women with a history of recurrent UTIs were 75% as likely to get a UTI if they drank 2 cups of cranberry juice than if they drink water.
*Individuals ingesting cranberry products were 62% as likely to get UTIs as those who did not.
*For women with a history of recurrent UTIs, those who ingested cranberry products were 53% as likely to get an STI during the study as those who did not.