Cranberry juice or vitamins for UTIs?

It is recommended that even an elderly person consult his or her doctor about trying cranberry treatment.

UTI_521 (photo credit: MCT)
(photo credit: MCT)
My 86-year-old mother suffers frequently from urinary tract infections (UTIs). I have been told that a tablet of “Cranberry Juice with Vitamin C” – which increases the urine’s acidity – can prevent further infections. The explanation was that vitamin C can inhibit the growth of harmful bacteria in the body. Which is better – cranberry juice or the vitamin tablet?

Can the cranberry juice interfere with the medications that people are already taking? My mother is taking Calcichew (calcium pills), steroids and tablets against water retention. I know that unfortunately, older people have no symptoms or mild symptoms until they are weak and lethargic; in my mother’s case, however, she had only a high temperature. Should an elderly person have regular urine tests to detect problems? Should they take supplements of vitamin C [even though] the ability to absorb this vitamin decreases with age? E.I., Givat Shmuel
Dr. Menachem Oberbaum, head of the integrative medicine unit at Jerusalem’s Shaare Zedek Medical Center, replies:
Urinary tract infections are the most common type of infections in older people. About half of elderly women experience at least one, and this frequency rises with age. Conventional treatment is to give a low dose of antibiotics for a long period, but most doctors don’t like to do this (because such a long course increases resistance to antibiotics). Cranberries contain tannins, which are substances that prevent E. coli bacteria – the most difficult pathogen in the urinary system – by sticking to tissues so the bacteria can’t enter. It is believed that there are additional mechanisms that increase the efficiency of tannins against other bacteria as well.
The Cochrane Review, which examined tannins, reported efficacy in the use of cranberries in preventing UTIs in a variety of populations, including children, pregnant women, the elderly, diabetics and people with urinary catheters. Its conclusion three years ago was that cranberries are also good for repeated urinary infections in young women. As for others, there is no proof due to the small number of clinical studies that were of high quality, and so no conclusions can yet be reached. This survey related to four studies on elderly patients; one showed that cranberries have no effect beyond a harmless placebo. The three others showed certain positive results. At the same time, the studies had too poor a methodological quality to reach conclusions on the basis of the work.
THE SITUATION is clearer regarding whether or not cranberries cause any side effects. All the studies show good tolerance for use in the short term. But in the long term, we see that 30 percent to 40% (just nine patients in the small study) discontinued the cranberry treatment. Many elderly people take Coumadin (Warfarin) pills for thinning their blood, and there is likely interaction between these and cranberries, with the risk of an increase in INR (the International Normalized Ratio used to monitor the effectiveness of blood-thinning drugs). Another problem is that the efficacy of cranberries depends on reaching a certain concentration of the active substances in the urine; kidney function in the elderly is often poor, so it may be that the necessary concentration is not achieved.
Despite all this, it is recommended that even an elderly person consult his or her doctor about trying cranberry treatment – while, of course, taking the above concerns into consideration. Antibiotic treatment as prevention has only a small advantage over cranberries and is itself not free of side effects; antibiotics can raise the risk of infection with Clostridium difficile bacteria, which is resistant to antibiotics.
As to the question of which is preferable – cranberry juice or the vitamin pill – the concentration of active ingredients in the pill is usually 30 times that of the juice. Regarding whether elderly people should undergo regular urine tests, the answer is that 25% of old age home residents will have bacteria in their urine without showing any symptoms; the general policy is not to treat such cases. So it is recommended to give a urine test only when there are symptoms.
About taking vitamin C supplements – there is no serious evidence of its efficacy in preventing recurring urinary infections. At the same time, taking a reasonable amount won’t hurt (except the pocket or purse), as it is water soluble, and excesses are easily removed with the urine.
Rx for Readers welcomes queries from readers about medical problems. Experts will answer those we find most interesting. Write Rx for Readers, The Jerusalem Post, POB 81, Jerusalem 91000, fax your question to Judy Siegel-Itzkovich at (02) 538-9527, or e-mail it to, giving your initials, age and place of residence.