New research confirms that cranberry juice helps prevent cystitis
Publication Date:25/01/2008
Drinking cranberry juice or taking cranberry capsules can reduce attacks of cystitis by about a third, a large review of studies has found. It seems to work best in women who get cystitis a lot and is less helpful in older people.
What do we know already?
Cystitis is an infection, usually caused by bacteria growing in your bladder. This causes inflammation and irritation. You might hear cystitis called a urinary tract infection.
Cystitis causes a burning pain when you pass urine. You might also need to pass urine frequently. Other symptoms include cloudy urine and blood In the urine. You might also have pain in your lower abdomen.
Although both men and women can get cystitis these infections are much more common in women. Children can also get urinary tract infections. Some women get cystitis a lot. If you get more than about two or three infections a year your doctor might say you have recurrent cystitis.
Cranberry juice and other cranberry products, such as capsules, have been used for several years to try to prevent and treat cystitis. Some previous research has found that cranberry products can help. The present review looked at a large number of studies to try to establish if cranberries really do help prevent cystitis.
What did the study find?
Overall, the new study found that drinking cranberry juice or taking cranberry capsules can reduce the number of episodes of cystitis by a third.
Tell me more about the study's findings
The study also found that cranberry products seemed to work best in women who got cystitis a lot. They were less good at preventing infections in men and women over 60 years old and those who were in hospital and needed a catheter (a tube that carries urine from the bladder to the outside).
In one study among women who got a lot of cystitis 16 in 100 of those who drank a mixture of cranberry juice and loganberry juice got one or more infections in the next six months. Among those who didn't drink the juice, between 30 and 40 in 100 got an infection.
The amount of cranberry juice people in the studies drank ranged from 30 millilitres to 300 millilitres a day. The capsules used in the studies contained between 400 milligrams and 2,000 milligrams of cranberry extract.
Quite a lot of people in some studies stopped taking cranberry products. The main complaints were acid in their throat (reflux), nausea and an increase in bowel movements. Some people also said they didn't like the taste of the juice.
Where does the study come from?
The study was done by researchers from the University of Stirling in Scotland. It was published in the Cochrane Library by the Cochrane Collaboration, an organisation that evaluates medical research.
How reliable are the findings?
This review looked at 10 studies on cranberry products for preventing cystitis which included 1,049 people altogether. Most of the studies were good quality. But lots of people did not complete the studies which makes the findings less reliable.
There are still some things we don't know. For example, the research doesn't tell us how much juice you should drink or how many capsules you should take to prevent attacks, or how long you need to take them for.
What does this mean for me?
If you get cystitis quite a lot, say more than twice a year, then this study is important for you. It suggests that drinking cranberry juice every day or taking cranberry capsules could help to stop you getting more attacks. Bear in mind that some people in the studies complained of mild side effects.
What should I do now?
It might be worth having a trial of drinking cranberry juice every day or taking cranberry capsules to see if this reduces the number of times you get cystitis. Unfortunately there's not enough research to say how much juice or how many capsules you should take to reduce your risk of getting cystitis.
There are some other things you can do to try to prevent cystitis. If you are a woman, always wipe from front to back after a bowel movement to reduce the chance of bacteria spreading. And passing urine after sex might help although there's no research to show if it does. If none of these measures help and you get repeat attacks of cystitis, your doctor might suggest you take a low dose of antibiotics for a few months.
Cystitis usually goes away on its own in about three days. Traditional advice for this infection includes drinking plenty of fluids, although there is no research to show if this helps or not. There are also remedies you can buy from a pharmacy that may help relieve symptoms.
However, it's important to see a doctor straight away if you are pregnant and have cystitis, or if you have signs of an infection in your kidneys, such as a high temperature and pain. You might need a course of antibiotics.
From:
Jepson RG, Craig JC. Cranberries for preventing urinary tract infections. In: The Cochrane Library, Issue 1, 2008. Wiley, Chichester, UK.
To find out more, see our information on cystitis.
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This information does not replace medical advice. If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.
