A new study suggests that drinking cranberry juice has a modest preventative effect in women with a history of recurring UTI. That being said, it is important to point out that Ocean Spray Cranberries funded the study. This means that there was a vested interest for a positive result from the trial.
Bladder irritation, or cystitis, is very a very common condition, especially in women. A urinary tract infection (UTI) is common type of bladder infection. It is estimated that 25% to 33% of women that have at urinary tract infection will have a recurrent UTI within six months.
For the six-week study, 185 women would drink a 240ml bottle of cranberry juice, and 188 others would consume an identical-tasting placebo daily. The researchers estimated that women who drank cranberry juice daily for 3.2 years would prevent one UTI.
There are some other key points with the study:
- Firstly, the cranberry juice used in the study was an additive-ridden, high-sugar drink.
- There were fewer additives in the cranberry juice than other products, but people must also consider the long-term effects of consuming a high-sugar drink on a daily basis.
- The women with UTI’s were still given antibiotics for the infection.
In the current study, cranberry juice would only prevent UTIs, and not treat them. The beneficial effect of cranberry juice likely came from a component called proanthocyanidins, which interfere with bacteria sticking to the cells of the urinary tract lining or bladder wall. Antibiotics on the other hand, will kill all the bacteria in the body—even the good bacteria that prevent the overgrowth of harmful bacteria. If you do take antibiotics for a UTI, it is especially important to take probiotics to replenish the lost beneficial bacteria in the body.
However, cranberry juice will not prevent bacteria from sticking to all the bladder cells. That is why the scientific support for cranberry juice in the treatment and prevention of a UTI is somewhat mixed. Some studies have suggested that cranberry juice may reduce the number of UTI symptoms over a 12-month period in women with recurrent infections; however, other studies suggested that cranberry juice is less effective than the previous studies had indicated.
Frequent UTIs have multiple causes, including an abnormal urinary tract function or shape, bladder or kidney stones, changes in estrogen levels during menopause, and bacteria entering the urethra during sex.
Besides cranberry juice, there are other natural UTI treatments available, including D-mannose, uva ursi, Echinacea and goldenseal, oregano oil, vitamin A, and vitamin C.
The study was published in The American Journal of Clinical Nutrition.
Maki, K.C., et al., “Consumption of a cranberry juice beverage lowered the number of clinical urinary tract infection episodes in women with a recent history of urinary tract infection,” The American Journal of Clinical Nutrition, 2016, doi: 10.3945/ajcn.116.130542.
“Cranberry juice ‘useful’ for women with recurring UTIs, claims study,” PubMed Health, June 20, 2016; http://www.ncbi.nlm.nih.gov/pubmedhealth/behindtheheadlines/news/2016-06-20-cranberry-juice-useful-for-women-with-recurring-utis-claims-study/.
Jepson, R.G., et al., “Cranberries for preventing urinary tract infections,” Cochrane Database of Systematic Reviews, 2012, doi: 10.1002/14651858.CD001321.pub5.