Cranberry juice really does lower your risk of urinary tract infections

People who regularly drink cranberry juice or take cranberry capsules are less likely to get urinary tract infections, according to experts from the National Taiwan University Hospital.

Cranberry products decrease risk of urinary tract infections

Urinary tract infections (UTIs) are very common, particularly in women. A UTI develops when part of the urinary tract becomes infected. E. coli bacteria cause over 80 per cent of all urinary tract infections.

Cranberry juice and cranberry capsules have long been a popular remedy for treating UTIs, but up until now researchers have not been sure how they work.

In the latest review in Archives of Internal Medicine, scientists looked at 10 head-to-head trials of cranberry products vs. no treatment in 1,500 volunteers.

Overall, the participants that were assigned cranberry products had 38 per cent fewer UTIs. For women with a history of recurrent infections, the risk was reduced by 47 per cent whilst taking cranberry products.

It is now thought that cranberries contain a substance that can prevent E. coli bacteria from sticking on the walls of the bladder. Laboratory studies show that the anti-adhesion activity of cranberry lasts for around eight hours after ingestion.

Whilst the results of the study solidify popular folklore medicine, they do need to be treated with caution. The amount of cranberry compounds used in the studies varied greatly, from one-gram capsules to close to 200 grams of cranberry juice daily.

Scientists now have to find the optimum dose of cranberry. Cranberry juice appeared to be slightly better than tablets of capsules containing the product, but more studies will be needed to confirm this.

Dr Ruth Jepson of the University of Stirling has been carrying out a similar review into cranberry juice. She said: "I'm not sure how many of us would want to be drinking this every day for an indeterminate amount of time.

“It can be costly and calorific and some people just don't like the taste of it."

UTIs will usually pass within a few days or can be easily treated with a course of antibiotics. People with or without health insurance should visit their GP if they suspect they have a urinary tract infection.