Benefits And Side Effects Of Cranberry Juice

Cranberries have long been touted as an effective way to keep urinary tract infections at bay; however, research is mixed, so it's difficult to tell if cranberry juice is truly beneficial or just another urban legend. Since cranberry juice is filled with the same vitamins and minerals frequently found in fruits, it's definitely worth adding to your diet year-round and not just on holidays.

Identification

The cranberry is a fruit native to North America that belongs to the same genus as the blueberry and was used by American Indians as food and for the treatment of bladder and kidney diseases. The berries and their juice contain several chemical compounds called phytonutrients that have antioxidant, anti-inflammatory and other health benefits. Cranberries are also an excellent source of vitamin C and contain some manganese and vitamin K. The juice of the fruit is acidic and bitter, which is why it's often manufactured with sugar or artificial sweeteners.

Urinary Tract Infections

About one-quarter of women will have a urinary tract infection, or UTI, at some point in their lives, according to the journal "Age and Ageing." Although women have used cranberry juice for centuries to prevent and treat UTIs, scientific research is mixed. One study, published in "Clinical Infectious Diseases" in January 2011, concluded that college women with an acute UTI who drank 8 oz. of 27 percent cranberry juice twice daily did not experience a decrease in the six-month incidence of a second UTI, compared with those drinking a placebo. However, other studies, such as one published in "Cochrane Reviews" in 2008 reported there is some evidence cranberry juice may decrease the number of symptomatic UTIs over a 12-month period, particularly for women with recurrent UTIs.

Other Potential Health Benefits

One of the ways cranberry juice may help prevent UTIs is by preventing bacteria from adhering to the walls of the bladder. This same effect may also transfer to stomach ulcers caused by the bacteria Helicobacter pylori and to the prevention of cavities caused by bacteria forming plaques on tooth surfaces, according to the Beth Israel Deaconess Medical Center. Researchers at Worcester Polytechnic Institute in Massachusetts reported at a meeting of the American Chemical Society in 2010 that cranberry juice cocktail blocked a strain of Staphylococcus aureus from beginning the process of infection in urine. Scientists have also studied the potential effects of cranberry on cancer. A study published in 2004 in the "Journal of Nutrition" showed that cranberry extracts decreased the growth and metastasis in the lab of breast, skin, lung, colon and brain human tumor cell lines.

Possible Side Effects

Side effects from cranberry juice are rare, although consuming large amounts could irritate heartburn, due to the high acid content. Cranberry juice varieties sweetened with sugar could affect blood glucose levels in diabetics. Cranberry concentrate tablets may increase your risk of kidney stones, although this hasn't been documented in people drinking cranberry juice. There has been concern for years that cranberry could cause bleeding in patients on the blood thinner warfarin. However, a randomized, double-blind trial published in the "Journal of Clinical Pharmacology" in July 2009 found there were no significant interactions between the juice and warfarin levels in the blood.