What do phytonutrients from fruits and vegetables do for your dog?
Fruits and vegetables provide much more than just fiber for your dog! They also contain phytonutrients, substances like carotenoids and polyphenols, which increasing research shows contribute to, among other things, the immune system and vision of dogs (Tanprasertsuk et al., 2022).
What exactly are phytonutrients?
Phytonutrients are substances that naturally occur in fruits, vegetables, grains, legumes, nuts, and seeds. They are not strictly essential like proteins or essential vitamins, but there is growing evidence that they do offer health benefits (Tanprasertsuk et al., 2022).
Two large groups are consistently highlighted in research. Carotenoids are the fat-soluble pigments that give fruits and vegetables their yellow, orange, and red colors, such as beta-carotene, lutein, lycopene, and zeaxanthin. Polyphenols are another group of antioxidants found in blueberries, pomegranates, turmeric, spinach, and broccoli, among others (Tanprasertsuk et al., 2022).
And importantly: dogs can truly utilize these substances, just like humans. Multiple studies in beagles showed that lutein, beta-carotene, and astaxanthin are found in the blood in a dose-dependent manner after oral intake. This means dogs can indeed absorb, store, and process phytonutrients (Tanprasertsuk et al., 2022).
What do carotenoids do for your dog's immune system?
This is one of the strongest findings from the research. Beta-carotene and lutein were found to increase both humoral immunity (more antibodies after vaccination) and cellular immunity (more lymphocyte proliferation) in dogs (Tanprasertsuk et al., 2022).
Specifically for lutein, even more immunomodulatory effects were found in female beagles: a stronger immune response to immune stimuli, increased production of immunoglobulin G, and a larger population of certain immune cells (Tanprasertsuk et al., 2022).
This has also been investigated in older dogs. A diet containing spinach flakes, tomato pulp, grape pulp, carrots, and citrus pulp, combined with environmental enrichment, resulted in increased neutrophil phagocytosis and a larger B-cell population in older beagles, both crucial components of the immune system (Tanprasertsuk et al., 2022).
What about your dog's vision?
This was also positive! A six-month study in healthy adult beagles showed that a mix of lutein, beta-carotene, zeaxanthin, and astaxanthin led to improved retinal function, both in light and dark conditions, and less change in the eye's refractive error, compared to dogs on a diet without these antioxidants (Tanprasertsuk et al., 2022).
What more research is needed for?
Research into a supplement containing omega-3, taurine, and carotenoids in growing puppies showed no clear effect on body weight, but did indicate a more favorable fat percentage and cholesterol profile (Tanprasertsuk et al., 2022). This type of research is promising, but still very much in development.
What does this mean for VerdaDog's food?
This is precisely why at VerdaDog we consciously choose fruits and vegetables as a base, not only for the fiber, but also for these naturally occurring phytonutrients. Curious about the composition of our kibble? View them here! Do you have a specific question about your dog's diet? Then check our FAQ page or contact us.
Frequently Asked Questions
Are phytonutrients also found in meat?
No, phytonutrients are by definition plant-based substances. A dog that primarily eats meat-based food will therefore only ingest these substances if the food also contains fruits or vegetables.
Does my dog absolutely need phytonutrients to stay healthy?
No, they are not considered essential nutrients like proteins or vitamins. However, research shows that they can offer additional health benefits beyond basic needs, which is very positive (Tanprasertsuk et al., 2022).
Can too much beta-carotene be harmful to my dog?
With prolonged very high intake, a harmless condition has been described where the skin takes on a yellowish color, called carotemia. This is described in the literature as a harmless phenomenon, not a health risk (Tanprasertsuk et al., 2022).
Is there a difference between phytonutrients from whole vegetables and from supplements?
Possibly. Researchers point out that the absorbability of these substances may differ between their natural form in whole fruits and vegetables and an isolated extract or supplement form (Tanprasertsuk et al., 2022).
About the author
David is the founder of VerdaDog. He grew up with a dog that struggled with allergies, which made him think about how he could prevent that with his own dog. He himself has been eating plant-based for over ten years, and this interest in nutrition, for himself and his dog, forms the basis of VerdaDog. This article is written based on peer-reviewed research. David claims no veterinary or scientific expertise and always refers to a veterinarian for medical advice.
Literature
Tanprasertsuk, J., Tate, D. E., & Shmalberg, J. (2022). Roles of plant-based ingredients and phytonutrients in canine nutrition and health. Journal of Animal Physiology and Animal Nutrition, 106(2), 586–613. https://doi.org/10.1111/jpn.13626
