Berry Juices And Fermented Dairy Products Likely To Reduce Recurring Urinary Tract Infections In Women
A recent study involving 139 women (mean age 30.5 years) indicated that subjects who consume fresh juices, especially berry juices, and fermented milk products containing probiotic bacteria, experience significantly less recurrence of urinary tract infections (UTI) than did women who consume these food items infrequently. In this study, consumption of fermented dairy products (e.g. yogurt) at a frequency of 3 or more times per week was associated with a 79% reduction in risk of UTI, compared to women consuming fermented dairy products less than once per week. For every deciliter of fruit juice consumed, women also appeared to reduce their risk of UTI by 34%, as an independent risk factor for this condition.
The plausible mechanism of prevention provided by these foods has been suggested, by the authors of this study, to involve a number of factors. Most berries, especially those of the genus Vaccinium, are rich in flavonoids, such as epicatechin (also found in green tea), which is a potent inhibitor of the adhesion of coliform bacteria to human cells. Plants produce flavonoids in response to microbial infection, suggesting a role for these substances in antimicrobial defense. As a rule, berries are a rich source of epicatechin, however, apples, cherries, and plums also contain respectable levels in the world of fruit. Therefore, it is thought that higher circulating levels of epicatechin may reduce the tendency of bacteria to adhere to the wall of the urinary tract, and thereby reduce the chance of UTI.
In this study, milk was not associated with a decreased risk of UTI or reduced risk of recurring UTI, however, the use of fermented dairy products was associated with a significant reduction in risk of UTI. This evidence suggests that fermented dairy products are able to favorably alter the microflora concentration of the large bowel due to their concentration of live gut-friendly bacteria (e.g. lactobacillus acidophilus). Lactobacillus bacteria is known to colonize in the large intestine and crowd out other non-desirable bacteria, including coliform bacteria, which is the bacteria responsible for UTI infections.
UTIs are an ascending infection caused by bacteria in the stool, which enter the urinary tract. Thus, any intervention that decreases the fecal concentration of coliform bacteria (e.g. lactobacillus acidophilus), and/or reduces the ability of coliform bacteria to adhere to the wall of the urethra (epicatechin), are likely to be useful interventions in the prevention UTI and recurring UTI, as suggested in the study by T. Kontiokari, J Laitinen et al.
Historically, women (mostly on the advice of holistic health practitioners) have used cranberry juice and cranberry juice extract products to help reduce recurrence of UTI, and some small clinical trials support this intervention. This present study published in the American Journal of Clinical Nutrition lends significant scientific support to suggest that dietary interventions of this nature should be considered as a safe and effective means by which women can reduce UTI infections and recurring UTI infections.
An important side note of this study indicated that frequency of intercourse was also associated with UTIs. Women having intercourse 3 or more times per week had a 2.7-times greater chance of developing UTIs, than did women having intercourse less than once per week. This is believed to be related to the physical transfer of bacteria from the large bowel to the urethra. Thus, attention to hygiene in this regard is also likely to help women reduce their risk of UTI in women engaged in an active sex life that includes frequent intercourse. Some gynecologists encourage patients to wash themselves after any sexual activity involving the vaginal region.
More than half of all women experience at least one urinary tract infection during their lifetime. As such, holistic practitioners should be aware of the natural interventions that have been shown to be effective in helping women reduce their risk of infection and recurring UTIs. The recent study by T. Kontiokari, J Laitinen et al, provides evidence that the frequent consumption of fruit juices, especially berry juices, as well as the frequent use of fermented dairy products, should be considered important natural and safe interventions to help women reduce their risk. Due to the high frequency of UTIs in North America women, health practitioners should consider educating their female patients on the evidence-based research pertaining to the role of nutrition and supplementation as a means to help reduce the risk and recurrence of this common and often stubborn problem.
Kontiokari T, Laitinen J, et al. Dietary factors protecting women from urinary tract infections. Am J Clin Nutr 2003;77:600-4