The health properties of cranberries

by Heather S. Oliff, PhD

The Health Properties of Cranberries Cranberry is one of the 10 most popular herbal supplements sold in the United States. It is known primarily as a simple, non-pharmacologic means to prevent or treat urinary tract infections, but scientists have recently discovered that cranberries may also prevent dental plaque.

The cranberry is a bitter red berry from the low-growing plant Vaccinium macrocarpon, which is native to North America; approximately 98% of the worlds cranberry supply is cultivated in natural and artificial bogs in the northern United States and Canada.

Urinary tract infections (UTIs) occur when the kidneys, ureters, bladder, or urethra

In one research study, more than 50% of the patients diagnosed with UTI were completely relieved of symptoms after drinking 16 ounces of cranberry juice daily for three weeks. Another 20% of the patients experienced moderate improvement.

Researchers originally thought that cranberry juice was making the urine more acidic, thereby killing the bacteria. However, this turned out not to be the case.

It appears that cranberry juice prevents UTIs by inhibiting bacteria from adhering to the urinary tract. One of the compounds responsible for this effect is proanthocyanidin, a type of tannin. As a result, bacteria are flushed out during urination, thereby preventing infection.

UTIs are typically treated with antibiotics that destroy the bacteria. Cranberry juice, therefore, provides an alternative approach to treating UTIs because it prevents the infection in the first place and eliminates the need for antibiotics.

Unsweetened cranberry juice is bitter and difficult for most people to drink. But the good news is that drinking 10 ounces of commercially available (sweetened) cranberry juice cocktail has been shown to reduce the incidence of UTI.

Not all cranberry juice beverages contains the same amount of actual juice, though. Check the label. One clue is the word "cocktail." Cranberry juice cocktails typically contain less juice (because theyre sweetened with water and sugar) than 100% cranberry juice blends (which are sweetened with other juices).

If you dont like the taste of cranberry juice drinks, one study has shown that 400 milligrams twice a day of encapsulated cranberry extract powder can also reduce the occurrence of UTIs. However, only 10 people participated in the study

There are no known side effects from drinking cranberry juice or taking cranberry juice extracts at therapeutic doses. Diarrhea or mild gastrointestinal upset can occur if more than three to four liters of juice is consumed per day

Soon after you brush your teeth, a thin layer of film

Realizing that cranberry juice prevents bacteria from adhering to the urinary tract, Dr. Ervin I. Weiss and his colleagues wondered if cranberry would have the same effect in the mouth. The researchers tested 23 different bacterial strains that live in the crevices between teeth. Rather than using whole cranberry juice, they isolated an active ingredient and used this cranberry juice constituent in the experiments. In a test tube, the bacteria were combined with the cranberry juice constituent. The researchers also combined bacteria with apple juice for comparison.

Only the cranberry juice constituent was able to reverse coaggregation of a large proportion of dental plaque bacteria. Reducing the quantity of bacteria making up the plaque should thereby decrease risk for dental disease.

Cranberry juice cocktail is probably not suitable for oral hygiene because it is sweetened to minimize the tart taste, and sugar promotes the accumulation of plaque and the development of cavities. Although Weiss findings indicate that cranberry juice extracts may play an important role in reducing dental plaque, human studies are still necessary to confirm this potential new role for cranberries.

Watch for exciting new dental care products containing cranberry juice constituents to decrease the incidence of dental disease. Until then, the only ways to effectively decrease dental plaque are to brush and floss daily and to have regular dental check-ups.