Botanical name(s):

Vaccinium macrocarpon, vaccinium oxycoccos. Family: Ericaceae

Other name(s):

bearberry

General description

The cranberry is an evergreen plant. It’s native to the northeastern U.S. The red berries on the plant are used in foods, drinks, and herbal products. It’s been used to prevent and treat urinary tract infections (UTIs). Cranberry has fallen in and out of favor in medicine. Today it’s recognized as an effective way to help prevent UTIs, especially in older women.

Cranberries are considered a foodstuff. They’re used in commercial quantities for cooking. They are used as a garnish for salad. They’re also used in gelatin salad, cranberry sauce and jelly, and cranberry cocktail. Cranberry cocktail is the most often used cranberry source to prevent UTIs. Strong cranberry extracts are also available. They can be taken as pills by people who don't like cranberry juice.

Cranberry contains many elements. These include anthocyanin, catechin, triterpenoids, and quinic acid. These have been shown to decrease how much bacteria stick to the bladder walls. This reduces the risk of UTIs.

Medically valid uses

There is some support that cranberry can help prevent UTIs. Note that this isn’t definitive. More research is needed.

Cranberry juice keeps bacteria from clinging to the bladder walls. It also increases the acidity of the urine. Cranberry is most useful as a preventive measure rather than a cure for an existing UTI. But taking cranberry with standard treatment for a UTI may help you get better more quickly.

Elements in cranberries have these features:

• They block certain chemicals needed for E. coli to attach to the bladder wall. This is a urinary infectious agent.

• They increase the acidity of urine. They do this by decreasing the pH.

• It may help prevent stomach ulcers caused by the bacteria H. pylori.  

• A few studies suggest that cranberry may decrease dental plaque. 

Unsubstantiated claims

There may be benefits that haven't yet been proven through research.

Cranberry juice may help cure yeast infections. When taken regularly, it’s said to prevent recurrent yeast infections.

The high levels of vitamin C in cranberry juice may aid in upper respiratory infections. It may reduce the frequency and severity of these infections. Cranberry may also help ease postnasal drip.

Cranberry juice may also help prevent kidney stones. It does this by reducing the amount of calcium in your urine and decreasing the pH of the urine. High levels of urinary calcium have been linked to kidney stones. So has high pH (alkaline) urine.

Dosing format

Cranberry comes in the form of berries, oral capsules (concentrated cranberry extracts), juice, and tea. For over-the-counter cranberry products, follow the dosing instructions on the package.

Cranberry juice may be suggested in amounts from 6 to 10 ounces total per day. It’s often taken in divided doses between meals.

Side effects, toxicity, and interactions

People who take blood thinners or aspirin should talk with their healthcare providers before using cranberry products.