Cranberries and UTI – Do they really help?
I think we’ve all suffered at the hands of a Urinary Tract Infection at some point, haven’t we? The unbearable urges, spending hours sat on the loo, waiting for the lacerating, glass-like sharpness to pass. Followed by the blood and abdominal cramping. I think its safe to say they can be pretty awful.
Working in urology I see many women who experience UTIs, many of them recurrently with some being as often as every few months. The most common form of treatment is of course, antibiotics, but when given repeatedly these can result in other symptoms such as oral thrush and gastrointestinal problems, not to mention the potential for antibiotic resistance to occur. If antibiotic resistance occurs, this means that recurrence of the infection is more likely and the cycle repeats.
But what is a UTI? What causes it? And can cranberry products really help to reduce symptoms or better still – can they prevent recurrence? I wanted to take a look at what the research evidence says, to investigate whether the use of cranberry is just an old wives’ tail or whether they actually can be of benefit.
UTIs are very common with up to 50% of women experiencing one at some point in their lives. Women are 50 times more likely to experience a UTI than men, as their urethras [the pipe which carries urine out of the body], is much shorter, meaning that bacteria may gain entry into the body more easily.
UTIs occur as a result of bacteria that normally dwell in the colon and rectum, entering the urethra, attaching to its wall and multiplying.
Symptoms of UTI
UTI may cause an array of very unpleasant symptoms including;
Burning and pain when passing urine
Abdominal or pelvic pain
Cloudy, smelly urine
Blood in the urine
Frequency and urgency to pass urine
In more severe cases, the bacteria can spread and a mild infection can progress into a more serious form of the condition such as;
Cystitis [inflammation of the bladder wall]
Urethritis [Inflammation of the urethra]
Pyelonephritis [inflammation of the kidney]
More serious symptoms may occur in these instances and may include;
Loss of appetite
There are several factors which may increase the risk of UTIs. These include;
Use of catheters
Poor hygiene practices and habits
Urological conditions and abnormalities
The use of contraception
Immunocompromised patients eg in those who are recovering from cancer or other illnesses
How does cranberry work?
Cranberries have been used for decades to help treat the symptoms of UTI in the form of juices, syrups and tablets and if you have suffered with an infection in the past its likely that someone has told you to “drink cranberry juice” at some point.
Cranberries are made up of 88% water, organic acids, fructose, Vitamin C and other chemicals called Proanthocyanidins [PAC]. These chemicals play an important defensive role against microbes within the plant, and it is these substances which are thought to be useful in treating UTI in humans. They work by stopping the bacteria from sticking and adhering to the wall of the urethra, and this prevents them from being able to multiply, colonise and cause an infection.
What does the research evidence say?
A useful literature review by Cochrane 2012 [reference below] looks at the current research evidence into the use of cranberry and its effects on UTI.
The paper reviewed 24 studies with a total of 4473 participants, investigating its usage in a range of populations, including the elderly, adults and children with catheters and in pregnant women.
The results of the study showed that there is some evidence to support the use of cranberry in reducing the number of symptomatic UTIs over a 12-month period, particularly in women who experience recurrent infections. However, as these results did not reach statistical significance, the use of cranberry should not be recommended for the treatment of UTI.
The study also concluded that there is some evidence to show that the effectiveness of cranberry in reducing recurrent UTIs in women and children, is not significantly different in comparison to antibiotic use.
This review did have limitations as many of the participants dropped out or had poor compliance as they did not want to consume the cranberry products long-term. Furthermore, many of the studies did not report the concentration of the active ingredient [PAC] within the cranberry products used, and so they may not have been potent enough to be effective.
In conclusion, the research supports the use of cranberry in the prevention of recurrent UTIs in women and children, however this conclusion is weak as the evidence is limited. More research is therefore required to investigate different potencies of cranberry products and larger scale studies are required to compare the effectiveness of cranberry, compared with antibiotics, before firmer conclusions can be drawn.