Antibiotics are widely regarded as one of the great success stories of the last century. And rightly so: since their introduction into medical practice just a few decades ago, they have revolutionised the treatment of conditions such as pneumonia and meningitis, and countless lives have been saved.

But despite their undoubted place in modern medicine, there is growing concern that the widespread use of antibiotics is leading to the emergence of an increasing number of superbugs - infectious organisms that are immune to the effect of antibiotic drugs. Because of this, doctors are being urged to curb their antibiotic-prescribing habits.

Given current medical thinking, it makes increasing sense to give natural approaches to common infections due consideration. Infection in the bladder, commonly referred to as cystitis, deserves special mention in this context. Cystitis affects more than half of all women at some point in their lives, and is the second most common reason women take antibiotics. Natural help is available for cystitis, though, in the form of cranberry; this tart little fruit has been recommended for cystitis since way before antibiotics came of age. Recent evidence suggests that the benefits of cranberry are not merely the stuff of folklore either. Several scientific studies have now shown that cranberry can help to protect against cystitis and reduce the need for antibiotic treatment in the long term.

Cystitis, the medical term for which is urinary tract infection (UTI), is almost always caused by bacterial organisms. Typical symptoms are discomfort on passing water and frequent and/or urgent urination. The vast majority of UTIs are caused by an organism called Escherichia coli (E coli). E coli makes its way into the bladder from the outside by migrating up the urethra - the tube that takes urine from the bladder to the outside. However, even if E coli does manage to get access to the bladder, it has to stick to the bladder wall before it can set off a full-blown infection. E coli has the ability to form finger-like projections called fimbriae, and it uses these to literally grab hold of the bladder lining.

One simple measure that can be taken to keep E coli from infiltrating the bladder is to drink plenty of water. This, quite simply, tends to flush the organism out of the urethra and bladder before it has a chance to get a grip. Between one and two litres of water each day is probably enough to exert significant protective effect here. Urinating as soon as possible after sexual intercourse is of particular importance as well, because sex increases the risk of E coli being introduced into the urethra and bladder.

As an adjunct to these simple measures, cranberry also appears to offer real potential for protection against cystitis. Cranberry is rich in substances called proanthocyanidins which reduce E coli 's ability to form fimbriae, thereby preventing it from getting its sticky little fingers into the bladder wall. The evidence suggests that this disabling effect of cranberry can dramatically reduce the risk of UTIs. In one study a daily dose of 300ml of cranberry juice effectively halved the number of UTIs and the need for antibiotics in a group of women. More evidence for the benefits of cranberry came from another study recently published in the British Medical Journal . Here, 50ml of a concentrated mix of cranberry (and some added lingonberry) juice taken each day also halved the number of bladder infections.

Cranberry juice is widely available and taking a glass or two of it each day may indeed help keep cystitis at bay. However, personally, I do have reservations about taking cranberry in this form. Most commercially available cranberry juices contain only about a quarter cranberry juice, with the rest of the liquid often being made up of sweetened water. Refined sugar is likely to have a number of adverse health effects in the long term, and my preference is to avoid it whenever possible. Plus, there is some evidence to suggest that the processing of cranberry juice may remove or deactivate a proportion of its active ingredients.

To my mind, cranberry extracts (usually in tablet or capsule form) are a better bet for many people. One supplement I like to use in practice is called Cran-Max, which is actually a powdered concentrate carefully prepared from the whole cranberry fruit. A recent study compared the protective effects of Cran-Max with low dose antibiotic therapy. Of 12 women treated with a daily dose of 500mg of Cran-Max for six months, only one had another bout of UTI. In contrast, women treated with antibiotics suffered from an average of two UTIs per person during the same time period. Cran-Max is available by mail order on 0800 085 2370.

Dear John...

I frequently suffer with bloating and discomfort in my abdomen. This usually occurs in the afternoon, after I've eaten lunch. Could it be caused by a food intolerance? What do you recommend to ease the symptoms?
Pam by email

Abdominal bloating can be caused by a myriad of problems, including excessive fermentation in the gut, poor digestion and stress. Your suggestion that your symptoms might be caused by food intolerance (undesirable reactions to specific foods) is a good one: my experience is that this problem is actually the most common cause of symptoms such as abdominal bloating and discomfort.

While any food may give rise to a problem with food intolerance, my experience is that the number-one offender in terms of digestive strife is wheat.

If, like a lot of people, you tend to eat wheat at lunch (such as bread or pasta), but generally avoid it at other times of the day, then this may well point to a problem with wheat sensitivity.

You might like to try eliminating it from your diet to see what effect this has. 100 per cent rye bread and non-wheat pasta (these are often made of corn or rice) might be good alternatives and can be found in most health-food stores and some supermarkets.

If wheat sensitivity is indeed the culprit, you can expect to see some improvement in your symptoms within a matter of a few days.

Nutrition news: Sauce of good health

In recent times there has been a flurry of interest in the role of the antioxidant nutrient lycopene in reducing the risk of prostate cancer. Tomatoes are rich in lycopene, and tomato-based sauces are likewise believed to contain significant levels of the nutrient. One study has found that men with high intakes of tomato sauce have a significantly lower risk of contracting prostate cancer than men with low intakes. In another recent study published in the Journal of the National Cancer Institute men with prostate cancer who ate tomato sauce every day were found to have lower levels of prostate-specific antigen (PSA) - a substance that reflects prostate cancer activity - compared to other men. So, tomato sauce may well play a role in both the treatment and prevention of prostate cancer.

· If you have any issues you would like Dr John Briffa to address in this column, please contact him by email on life@observer.co.uk. Please note that Dr Briffa cannot enter into any personal correspondence.