The research suggests that a key chemical contained within the fruit: phytochemicals known as proanthocyanidins (PACs); these are similar to the chemicals found in red wine. The chemical appears to hinder bacteria from sticking to the walls of the urinary tract. Proanthocyanidins
also seem to have antioxidant properties.
This was shown through a study
whereby cranberry powder was shown to inhibit the ability of Proteus mirabilis
(a bacterium frequently implicated in complicated UTIs). In particular, increasing concentrations of cranberry powder reduce the bacteria's production of urease (a factor which allows the bacterium to move).
The implication of the study is that it could lead to the development of cranberry derivatives to be used to prevent bacterial colonization in medical devices such as catheters. Some work has indicated that cranberry-enriched silicone substrates impaired the spread of certain bacteria.
In addition to PACs, raw cranberries
have moderate levels of Vitamin C, dietary fiber and the essential dietary mineral, manganese, as well as a balanced profile of other essential micronutrients in minor amounts.
The study was carried out by researchers based at McGill University's Department of Chemical Engineering. The findings have been published
in the Canadian Journal of Microbiology. The paper is titled “Cranberry impairs selected behaviors essential for virulence in Proteus mirabilis