Common Names: cranberry, American cranberry, bearberry

Scientific Names: Vaccinium macrocarpon (also known as Oxycoccus macrocarpos), Vaccinium oxycoccos

Background

• Cranberries grow on evergreen shrubs found in wet environments, primarily in northeastern and north-central regions of North America.

• Historically, Native American communities and European settlers used cranberries both as food and medicine. Traditionally, cranberries were believed to help with issues related to the bladder, stomach, blood, and liver, as well as with conditions like wounds, diabetes, and scurvy.

• Nowadays, cranberry products are widely promoted to support urinary tract health, particularly in preventing UTIs. This interest stems from a need for alternatives to antibiotics due to the rise of antibiotic-resistant bacteria.

How Much Do We Know?

• Numerous studies have explored the potential of cranberry in preventing UTIs, especially among women who suffer from them frequently. However, many of these studies vary in quality.

• There is limited research evaluating cranberry’s impact on other health conditions.

What Have We Learned?

• Overall, cranberry may reduce the chance of recurrent symptomatic UTIs in women by around 25%, sometimes even more. Nonetheless, findings across studies are not always consistent, leaving the effectiveness open to question.

• Cranberry is not recommended for treating current UTIs; it may help prevent them but cannot cure an active infection.

• The compound thought to be beneficial, proanthocyanidins (PACs), may help prevent bacteria from adhering to the bladder lining. When cranberries are processed into capsules or powders, these beneficial compounds may become less concentrated, potentially reducing their effectiveness.

• Research involving certain vulnerable groups—such as older adults in care facilities or pregnant women—has produced mixed results. Other at-risk groups, such as women undergoing gynecologic procedures or individuals with multiple sclerosis, have not seen a benefit from cranberry supplementation.

• Since 2020, the FDA has permitted cranberry supplement manufacturers to state that limited evidence suggests a possible benefit in reducing recurrent UTIs in healthy women. Similar statements can be made for cranberry juice, provided the wording indicates that the findings are limited and inconsistent.

What Do We Know About Safety?

• Generally, consuming cranberry in normal amounts is considered safe. However, excessive intake may lead to digestive issues, especially in children.

• Anyone experiencing UTI symptoms should consult a healthcare provider for appropriate diagnosis and treatment. Cranberry should not replace proven treatment methods.

• There are mixed findings on whether cranberry interacts with the blood thinner warfarin. If you are taking any medications, particularly blood thinners, it’s essential to speak with a healthcare provider before using cranberry.

• While modest consumption of cranberry is likely safe during pregnancy or breastfeeding, the safety of higher doses is uncertain. Consult your healthcare provider if you plan to use cranberry in greater than typical food amounts during these times.

Keep in Mind

• Always communicate with your healthcare provider about any supplements or alternative therapies you are considering, so you can make informed decisions together.

• Herbal products are regulated differently depending on their ingredients, use, and how they are consumed. Many are categorized as dietary supplements, which are subject to less strict rules than pharmaceuticals.

• The FDA does not approve dietary supplements before they reach the market. However, if safety concerns arise, the agency can take steps to protect consumers. Manufacturers are responsible for ensuring their products are safe and properly labeled before sale.

For More Information

• Wise Use of Dietary Supplements

• Understanding Interactions: Medications and Supplements

• Interpreting Scientific Research Articles

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PubMed®

PubMed®, a service of the National Library of Medicine, contains summaries and publication data from scholarly journals in health and medicine. Resources are available to help navigate and interpret this content.

Office of Dietary Supplements (ODS), NIH

The ODS works to enhance public understanding of dietary supplements through scientific research, outreach, and educational tools. They offer information sheets and resources on many supplement topics including vitamins and minerals.

Key References

American Urological Association. Recurrent Uncomplicated Urinary Tract Infections in Women: AUA/CUA/SUFU Guideline (2022).

Caljouw MAA, et al. Study on cranberry pills for UTI prevention in older adults in care homes. Journal of the American Geriatrics Society. 2014;62(1):103-110.

Cranberry entry from NatMed Pro database. Accessed September 1, 2023.

Gbinigie O, et al. Feasibility study on cranberry extract and antibiotic use in UTI symptoms. BMJ Open. 2021;11(2):e046791.

Klein MA. Cranberry. In: Encyclopedia of Dietary Supplements. 2nd ed. Informa Healthcare; 2010:193-201.

U.S. Food and Drug Administration. Statement on cranberry supplements and UTI risk reduction. July 21, 2020.

Williams G, et al. Review on cranberries for UTI prevention. Cochrane Database of Systematic Reviews. 2023;4(4):CD001321.

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This information is shared by NCCIH to support public awareness. It should not replace professional medical advice. Always consult with a healthcare provider about any treatment decisions.