Forums

Guidance, support and wisdom to benefit and maximize the life and longevity of animals.

VetVine Client Care

Posted On Jul 15, 2022

Updated On Oct 21, 2025

Cranberries - The Health Benefits

Nutrition

The benefits of eating fresh fruits, vegetables, and whole grains and their impact on human health are well established. Consumption of these phytochemical containing foods correlates with improved cardiovascular health and a reduction in the risk for a variety of conditions including cancer and age-related degenerative diseases. While thousands of phytochemicals (bioactive, non-nutrient compounds from plants) have been identified and catalogued as potentially bioactive, only about 150 have been studied for their health benefits. With respect to veterinary use, the evidence is further limited by the lack of species-specific, placebo-controlled clinical trials. 

The exact mechanisms of various phytochemicals remain unexplained however there is a growing body of evidence that demonstrate their beneficial effects. Some of the benefits include:

  • AA = antiadhesion towards bacteria
  • AC = anticancer
  • AI = anti-inflammatory
  • AOX = antioxidant
  • AU = antiulcer
  • AV = antiadhesion toward viruses
  • CHB = cardiovascular health benefits
  • NFP = neural function protection

One fruit that imparts health benefits to humans and animals is the cranberry. The American Cranberry (Vaccinium macrocarpon) has a number of beneficial constituents or phytochemicals including:

  • Flavonoids - the most dominant component
    • Anthocyanins (e.g. peonidin) - cause the bright red color of the fruit. It is the most studied component; at least 13 have been identified. These compounds are strong antioxidants.

      • Potential health benefits: anticancer (AC), antioxidant (AOX), neural function protection (NFP), and cardiovasular health benefits (CHB)

    • Flavonols / catechins. (e.g. quercetin) - cause yellowish pigments and AOX stabilizer. Cranberry flavonols are unique and present in high concentrations that are considered most significant to effects on health.
      • Potential health benefits: anticancer (AC), antioxidant (AOX), anti-inflammatory (AI), and cardiovasular health benefits (CHB)

    • Proanthocyanidins - also called condensed tannins. Causes astringent flavors and AOX stabilizer. 
      • Potential health benefits: antiadhesion towards bacteria (AA), antioxidant (AOX), anti-inflammatory (AI), antiulcer (AU), antiadhesion towards viral pathogens (AV), cardiovasular health benefits (CHB), neural function protection (NFP)

    • Polymeric Color Compounds - cause red-brown pigment and have strong antioxidant activity, however there are relatively few in vitro studies or clinical trials.
      • Possible health benefits: antiadhesion towards bacteria (AA), antioxidant (AOX), antiadhesion of viruses (AV)

  • Non-Flavonoids 

    • Non-Flavonoid Polyphenols - are antioxidant stabilizers and contribute astringent flavors. The best known are the bioactive stilbenes (e.g. reservatrol)
      • Potential health benefits: anticancer (AC), anti-inflammatory (AI), and antioxidant (AOX)

    • Simple Phenolics & Benzoates (e.g. salicylic acid) - cause aroma and are antioxidant stabilizers
      • Potential health benefits: anticancer (AC), anti-inflammatory (AI), antioxidant (AOX), and cardiovasular health benefits (CHB)

  • Non-Phenols
    • Non-aromatic Organic Acids (e.g. ascorbic acid / Vitamin C) - cause sour flavors
      • Potential health benefits: anticancer (AC) and antioxidant (AOX)

    • Complex carbohydrates (e.g. pectin) - causes gelation and edible films.
      • Potential health benefits: anticancer (AC) and antioxidant (AOX)

    • Sugars (e.g. fructose) - provides sweet flavors
      • Potential health benefits: antiadhesion towards bacteria (AA) and anticancer (AC)
         
  • Terpenes, Sterols and Terpene Derivatives
    • Terpenes and Terpene derivatives (e.g. ursolic acid) - provide much of the flavor and aroma
      • Potential health benefit: antiadhesion towards bacteria (AA), anticancer (AC), anti-inflammatory (AI), antioxidant (AOX), cardiovasular health benefits (CHB), and neural function protection (NFP)

    • Sterols - anti-inflammatory (AI), anticancer (AC), antioxidant (AOX)

 

Cranberry and cranberry extract supplementation has been suggested for use in humans as part of the management of urinary tract infections (UTIs). While it has been widely studied, the strength of the evidence to support its efficacy is mixed. Cranberry cannot directly kill bacteria and, therefore,  cannot replace antibiotics for treating active infections. It can, however, prevent bacterial adherence to uroepithelial cells (cells in the urinary tract). Studies of cranberry administration in humans have found modest reductions in UTI recurrence in women prone to recurrent infections. 

In veterinary medicine, commercial cranberry supplements (nutraceuticals) are available. Because they are categorized as a nutraceutical (vs. pharmaceutical) they are not required to demonstrate or report safety or efficacy information. The most current guidelines from the International Society for Companion Animal Infectious Diseases (ISCAID) regarding management of bacterial urinary tract infections in dogs and cats were published in 2019. Because of insufficient evidence of its effectiveness (as of 2018), cranberry could not be recommended for treating bacterial urinary tract infections / cystitis. However, they did state that there was no contraindication to the adjunctive use of cranberry supplements known to be safe.

This article published in 2025 discusses more about cranberries, its effects, and areas of attention in animal health.