A Season for Cranberry and Reasons to Eat Them
~ January 1999 No.63 ~
Cranberries traditionally have had their place as a condiment that accompanies turkey in many North American house holds. Mysteriously these red berries would appear in bowls handed around the table at Thanksgiving and Christmas meals, and would they disappear for another ten months. Then came the era of cranberry drink. It tasted sour and had an acquired taste, but more and more it found its way into shopping baskets because it added “such a nice colour” to a drink or punch.
Like so many fruits and vegetables that make up a good diet, researchers have found that cranberries may be good for health. This comes as good news to the over six million Americans, mainly women, who suffer from urinary tract infections. Bacteriuria (literally means bacteria -in this case harmful- in the urine) is common among elderly women both in and out of institutions. Recurrent urinary tract infection is particularly common in patients who suffer from incontenence.
A recently published article describes how older women who were at risk of developing urinary tract infection were asked to consume 300 mL of a cranberry juice cocktail every day for six months. The study was a well designed double blind protocol in which neither the subjects nor the researchers monitoring the subjects knew who was receiving which treatment (cranberry or look alike, taste alike placebo). Urinary tract infection was reduced in the group which was receiving the cranberry juice.
Bacteriuria was noted in 28% of urine samples in the placebo group and in 15% of the cranberry group. The difference was only found in samples taken after the first month of the study, and was sustained thereafter. Like so many other foods that are good for health, it appears that a daily dose is needed to provide ongoing benefits.
Researchers have looked for constituents in cranberry juice which might explain how the juice protects against bacterial infection. It is becoming clear that the effect is related to how bacteria attach themselves to tissues in the body. In this case, sugars in cranberry juice appear to be able to prevent bacteria from adhering to the bladder wall. They can't stick, are flushed out and, therefore, can't cause problems.
The scientific explanations as to why a particular food has a beneficial effect on health are often very complex. "Does it work?" is always the first question asked. It would appear that in the case of cranberries, they do reduce bacteriuria. So make sure you have cranberry sauce to accompany that holiday turkey.
|Botanical name:||genus Vaccinium, family Ericaceae; large or American cranberry V. mcrocarpon|
|Major growing areas:||Canadian province of Quebec, northeastern United States|
|Nutrient content:||(per 1 cup) energy 144 kcal, vitamin C 90 mg, vitamin A 10 IU, potassium 46 mg|
Prevention of recurrent urinary-tract infections in women.
Lancet 1999; 353: 7-8