Products
Preparations made from cranberries are commercially available as juice, capsules, tablets, powder and tea, among others. Dried and sugared cranberries are also available.
Stem plant
The American cranberry (large-fruited cranberry) Aiton from the heather family is native to North America and is cultivated on a large scale. The European cranberry L. is less common because it has been less scientifically studied. Caution: Cranberries are not the same as cranberries, which also belong to the genus! Another note: in German it is called cranberries, in English cranberries.
Medicinal drug
The fresh or dried, ripe fruits of are used as a medicinal raw material (Macrocarponii fructus).
Ingredients
The effects are primarily attributed to the A-type proanthocyanidins (PAC). These are a mixture of oligomers consisting primarily of epicatechin units. Other constituents include flavanoids, anthocyanins and organic acids.
Effects
Preparations of cranberries have antiadhesive, antimicrobial, anti-inflammatory, and antioxidant properties. The proanthocyanidins inhibit the attachment of bacteria to the urothelium of the urinary bladder. Several clinical studies have been conducted. Efficacy is controversial in the literature (e.g., Jepson et al., 2012).
Indications for use
For prevention and supportive treatment of recurrent urinary tract infections, especially cystitis in women. Cranberries are also used as a food and beverage. Available, for example, are snacks, fruit slices, syrups, drinks or cranberry sauces to accompany turkey at Thanksgiving (USA).
Dosage
According to the directions for use. Dosage depends on the product. In clinical trials, between 30 to 300 ml of pure cranberry juice was administered per day.
Contraindications
Preparations of cranberries are contraindicated in hypersensitivity and with a history of kidney or urinary stones. Evidence in children is insufficient and use is therefore not recommended. Full precautions can be found in the Instructions for Use.
Interactions
Drug interactions with vitamin K antagonists (warfarin) have been reported.
Adverse effects
Preparations of cranberries are usually well tolerated. Rarely, hypersensitivity reactions may occur. Cranberries have a sour taste. Therefore, many preparations are sweetened, diluted, or blended. The drop-out rate has been high in some studies, probably related to the taste.
