Cranberries and the Prevention and Treatment of Urinary Tract Infections

Crestina L. Beites, PhD

Clinical Question:
Can urinary tract infections be treated effectively with cranberry juice?

BACKGROUND
Long before early settlers in North America learned to use the cranberry, indigenous people were already reaping benefits from cranberry mixtures. They were mashing cranberries with wild game and animal fat to make pemmican, a high-energy, spoil-resistant survival food. They also used cranberries medicinally to draw poison out of arrow wounds and treat bladder and kidney ailments.1 Cranberry juice has since evolved into a quintessential North American folk remedy, and as early as the 1920s, it was being used to reduce the frequency of urinary tract infections (UTIs). Because acidic environments are detrimental to bacteria and because consumption of large amounts of cranberries was found to acidify urine, scientists hypothesized that cranberry-rich diets would eradicate Escherichia coli from the bladder. More than 60 years ago, this idea popularized the use of cranberries for treating UTIs. In the 1960s, cranberry consumption gained wide acceptance as a self-treatment for bladder infections.