Diet may play a role in the risk of contracting a urinary tract infection (UTI), an illness that will affect more than half of women at some point during their lives.
UTIs are caused by bacteria in the stool, and dietary changes can affect the bacterial flora involved, which is why researchers suggest that diet may affect risk.
Cranberry and cranberry-lingonberry juices have been found to be particularly effective in preventing UTI recurrence, as women who consumed fresh juices, especially from berries, were less likely to have experienced a UTI recently.
Most berries are rich in flavonols, such as epicatechin. Plants produce flavonols in response to microbial infection, which suggests that these substances may play a role in antimicrobial defense.
Further, epicatechin potent prevents bacteria like E. coli from attaching to human cells. Since the bacteria cannot attach to the lining of the bladder wall, they slide out of the bladder without causing an infection.
Although fruits such as apples, cherries, and plums are rich in epicatechin, the flavonol content of berries is higher, which may explain why berries are associated with a reduced risk of UTI recurrence.
Another dietary factor associated with a low UTI recurrence was frequent consumption of fermented milk products containing probiotics. No association was found from fresh milk products, leading researchers to suggest that the probiotics, rather than the milk itself, may be responsible for the protective effects.
Intakes of vitamins, minerals and herbal supplements, including daily calcium intake, did not have any effect on UTI risk, nor did total daily drinking volume.
Aside from diet, other risk factors for UTIs include sexual activity and contraception methods, genetic circumstances, such as belonging to blood groups AB or B, and age. Women between the ages of 25 and 29 years, and those older than 55 years, are most likely to be affected.
American Journal of Clinical Nutrition March 2003;77(3):600-4