Quercetin Exhibits Significant Anti-Inflammatory Properties - Research Reflection

By Juliet M. Getty, Ph.D.

Researchers from Christian-Albrechts-University of Kiel, Germany, revealed that dietary quercetin supplementation may be useful in controlling inflammatory disorders in horses.

Four adult Warmblood horses received hay ad libitum [free choice], along with concentrated feed twice daily and 8 hours of access to pasture. Quercetin was the only supplement given. The goal of this study was to determine, what, if any, effect quercetin has on plasma proinflammatory cytokines as well as on the accumulation of beneficial plasma flavonols.


Quercetin was shown to inhibit the synthesis of proinflammatory cytokines IL-1, IL-6, and TNF-alpha, as well as anti-inflammatory interleukin 10. From this study, it was concluded that daily quercetin supplementation of 10 mg per kg of body weight may have a significant impact on reducing inflammation throughout the body.

Implications for your horses

Quercetin belongs to a group of beneficial plant antioxidants known as flavonoids. It is typically found in the pulp of foods high in vitamin C, and is also included in vitamin C complexes and supplements designed for allergy relief. As an antioxidant, it has the potential to neutralize damaging free radicals, and activate antioxidative enzymes.

There are numerous equine inflammatory conditions which could be alleviated via quercetin supplementation. Its impact on reducing oxidative stress may lessen the potential for both equine Cushing’s disease and leptin resistance. The inflammation seen with arthritis, ulcers, muscle fatigue, and allergies may also be reduced by adding quercetin to the diet.

The amounts typically found in foods and human supplements are lower than the concentration used in this study. For this experiment, quercetin was administered at a rate of 10 mg per kg of body weight, amounting to 5,000 mg for a 500 kg horse (1100 lbs). This is approximately 10 times the recommended dose for human use, which is a typical level for many nutrients administered to horses.  

There are very few supplement companies that offer quercetin as part of their formulations, and if they do, it is at far lower concentration than this study suggests. Quercetin is available in bulk at various online companies.   


Wein, S., & Wolffram, S. 2015. A two-week quercetin supplementation in horses results in moderate accumulation of plasma flavonol. Journal of Equine Veterinary Science, 35(7), 617-621.


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