Cranberries are traditionally associated with Christmas dinner and roast turkey. They are used in many recipes – both in sauces and deserts – and are eaten fresh or dried or squeezed for their juice. In addition to their culinary uses, cranberries are increasingly recommended by doctors and complementary practitioners as a treatment and prevention for people who suffer from frequent bladder infections.
What’s it good for?
- Incontinence (deodorizes urine)
- Urinary tract infections
The cranberries, a shrub native to peat bogs and forests in North America, is now widely cultivated in Europe. You can grow it at home from cuttings, but it likes a damp acid soil. The shrub will survive extreme cold, though frosts can kill buds and warm sun is needed to ripen the berries.
The small dark red berries have been used medicinally for hundreds of years. As well as being prescribed for urinary infections, cranberries have been used for blood disorders, liver problems, stomach complaints and poor appetite. Cranberries reduce the odour of urine, so the juice is useful for those who suffer from incontinence. Constituents in cranberries also help to prevent tooth decay by stopping bacteria from sticking to the teeth so inhibiting plaque build-up.
The phytochemicals in cranberries include tannins and antioxidant anthocyanins (which aid night version) and the seed oil contains omega-3 fatty acids. The fruit is also a rich source of vitamin C. Pure cranberry juice is very acidic and so strong that it can erode dental enamel, which is one reason why cranberry drinks are usually diluted – often with sugar.
Combating bladder infection
Cranberries fight urinary tract infections in several ways. In the past it was thought that cranberries acidified urine, raising the level of hippuric acid, a substance that creates an inhospitable environment for E. coli and other bacteria that can colonize the urinary tract. But although cranberries is acidic, it does not seem to acidify the urine. Research is now focusing on other constituents of cranberries, particularly fructose and the fruit’s antioxidants. These ingredients have been shown to prevent bacteria not only from colonizing the urinary tract, but also from sticking to the bladder wall where they could otherwise reproduce. The barriers’ high vitamin C content may also boost the body’s immune system for fighting infection.
Research has proved that drinking a lot of cranberries juice can reduce the incidence of urinary tract infections in susceptible people. It also appears to shorten the duration of symptoms but, if you already have an infection, ask your doctor or pharmacist for advice. In this instance, cranberry is best used to bolster prescribed medication rather than as a cure.
Blood benefits
Research has shown that cranberry juice can increase the levels of ’good’ (HDL) cholesterol and blood antioxidants. Cranberry juice could thus help to prevent heart disease, but the amounts needed to show a beneficial effect in this study were quite large – 3 glasses of full strength juice a day for three months. Doctors also think that cranberries mat help both to reduce the severity of strokes and aid recovery from them.
How much, how often?
Most scientific studies looking at the prevention of urinary tract infections use 800mg cranberry extract a day. This is equivalent to drinking 500ml (18fl oz) undiluted cranberry juice twice a day. The juice sold in supermarkets is really too dilute to be effective. You can make your own using a juicer or buy full-strength juice from a health-food shop. If you find the juice too sour when undiluted, try mixing it in equal parts with pure bilberry juice, which has similar beneficial ingredients. Or mix the day’s allocation of cranberry juice with an equal amount of apple juice, which is naturally sweet.
Cranberries, even in large amounts, are usually very safe. But unfortunately, blood clot patients on warfarin must not take cranberry, either in drink, concentrate or capsule form, as cranberry can increase warfarin’s anticoagulant effect, causing severe bleeding. Also check with your doctor if you have prostate problems or severe kidney disease before taking cranberry juice. Drinking more than a liter a day for prolonged periods may also increase your risk of kidney stones because cranberries contain oxalates.
Cautions and Side Effects
Do not take if on blood thinning drugs.