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Cranberry should be avoided by people with an allergy or hypersensitivity to Vaccinium species (cranberries and blueberries) their parts, or members of the Ericaceae family. People who are allergic to aspirin should avoid drinking large quantities of cranberry juice.
Side Effects and Warnings
Patients with diabetes or glucose intolerance may want to drink sugar-free cranberry juice to avoid a high sugar intake. High doses of cranberry may cause stomach distress and diarrhea, or may increase the risk of kidney stones in people with a history of oxalate stones. Some commercially available products are high in calories. On average, six ounces of cranberry juice contains approximately 100 calories. One study showed the possibility for occurrence of vaginal yeast infections in those women who often consume cranberry juice, although this has not been proven. Use cautiously if taking anticoagulants (blood thinners) such as warfarin, medications that affect the liver, or aspirin. Use cautiously in patients with altered hepatic function or in those taking cytochrome P450-metabolized agents. Use cranberry juice cautiously due to the high sugar content, which may negatively affect dental health. Use cautiously in patients with rheumatoid arthritis, based on the potential for acidic juices to increase joint pain. Avoid in those with known allergy or sensitivity to Vaccinium species (cranberries and blueberries), their parts, or members of the Ericaceae family.
Pregnancy and Breastfeeding
Safety has not been determined in pregnancy and breastfeeding, although cranberry juice is believed to be safe in amounts commonly found in foods. Many tinctures contain high levels of alcohol and should be avoided during pregnancy.
This evidence-based monograph was prepared by The Natural Standard Research Collaboration