Cranberry is an evergreen shrub native to North America. It grows in bogs as a bush with upright branches. Pink flowers and red-black berries appear in June and July. Cranberry is related to the blueberry, buckberry, hackberry, and bilberry.
Why cranberry is used
Cranberries show up along with turkey and stuffing at many holiday meals. But in addition to being a popular side dish, cranberry has long been considered a natural remedy for a variety of conditions including urinary disorders and infections. Recently, cranberry has been used to try to prevent urinary tract infections and Helicobacter pylori (H. Pylori) infections that can cause stomach ulcers. Cranberry is also sometimes used to reduce dental plaque.
Cranberry fruit is a good source of vitamin C and is known to be high in antioxidants. Antioxidants help neutralize free radicals, which are dangerous particles in the body that can damage cells membranes, affect cell DNA, and even cause death. Researchers are trying to determine if these antioxidants in cranberry can help prevent heart disease and cancer.
Cranberry has long been believed to help prevent urinary tract infections (UTIs). Some studies indicate that cranberry can prevent bacteria from sticking to the walls of the urinary tract (the bladder and the tube that carries urine out of the body). Cranberry cannot cure UTIs, but some studies indicate that taking cranberry can help prevent UTIs.
However, researchers at the University of Michigan are now reporting that cranberry is no better than a placebo at preventing UTIs. The study followed 319 college-aged women who had formerly had a serious UTI. Some of the group drank cranberry juice twice a day for 6 months while the rest of the group drank a placebo that did not contain cranberry. The researchers were surprised to note that the group who drank cranberry actually had more repeated UTIs than the placebo group (19 percent vs. 15 percent). This group of researchers now claims that cranberry is not effective at preventing urinary tract infections.
How cranberry is used
Ripe cranberries are used to make a variety of food and medicinal products. Cranberries can be eaten fresh or frozen and can be found in juice and in concentrated forms. Dried berries are also available in capsules. Because cranberries are sour, sugar is often added, especially to cranberry juice drinks.
Cautions for cranberry
Cranberry as a food or supplement is generally considered to be safe. Cautions for cranberries include:
• Cranberry contains a chemical which may increase the risk of kidney stones. If you have had kidney stones in the past, talk to your doctor before using cranberry as a supplement.
• Cranberry may interfere with warfarin, which is a blood-thinner. Do not take cranberry as a supplement if you are taking warfarin.
• Talk to your doctor before adding cranberry as a supplement if you take medications that affect the liver or if you take daily aspirin.
• Diabetics should be careful when taking cranberry due to the large amounts of sugar that may be added to cranberry juice.
• Cranberry cannot cure urinary tract infections. Do not try to replace antibiotics with cranberry for UTIs.
An adult serving of cranberry as a supplement can be 3 or more ounces of pure juice or 10 ounces of cranberry juice cocktail. In capsule form,1,800 mg to 2,400 mg per day of cranberry can be taken, divided into six doses throughout the day. One and a half ounces of fresh or frozen cranberries count as one supplemental serving.
Be sure to tell your health care professionals about all medications and supplements you take, including cranberry.
Sources:
National Center for Complementary and Alternative Medicine
University of Maryland Medical Center
National Center for Complementary and Alternative Medicine: Research Spotlight