Curcumin, derived from the turmeric plant, is a spice that recently become popular to feed to horses as a dietary supplement. It has purported anti-inflammatory benefits and is used in horses with laminitis, arthritis, metabolic syndrome and other health conditions.

Turmeric has long been used in traditional herbal medicine to help relieve symptoms associated with digestive, skin, respiratory and joint disorders. There is growing medical and veterinary interest in turmeric for common disorders such as liver disease, skin problems, arthritis, infections, and digestive complaints. [1]

Turmeric contains more than 300 active compounds, the majority of which are polyphenols with antioxidant effects. Curcumin is the most well-studied polyphenol with extensively documented anti-inflammatory properties.

Horse owners typically feed turmeric supplements to help with osteoarthritis, joint stiffness or pain, skin irritations, sarcoids and ulcers.

While turmeric is well-researched in other species, there is limited clinical data about the effectiveness of this herbal extract on horses. This article reviews the academic research on turmeric and discusses the potential benefits for your horse.

Before adding a supplement containing turmeric to your horse’s feeding plan, consult with our equine nutritionists for free by submitting your horse’s diet online.

What is Turmeric?

Turmeric (Curcuma longa) is a plant that originates from Southeast Asia and is a member of the ginger family. The turmeric stem (known as the rhizome) is used as a spice in cooking and is considered to have medicinal properties in traditional herbal medicine.

Curcumin is one of the primary active compounds within turmeric. It gives turmeric its yellow colour and is the main source of medicinal properties. [1]

Interest in turmeric’s biological properties dates back to more than a century ago. Curcumin was first isolated from turmeric in 1815, and its chemical formula was identified in 1910.

By 1937, curcumin was credited with helping to treat biliary disease in 67 patients. It was recognized for its antibacterial properties in 1949, and in 1972 curcumin was identified as helping to reduce blood glucose levels in diabetic patients. [2]

More recently, curcumin has become a compound of interest in the veterinary world. It can now be found as an ingredient in companion animal feeds and in livestock and equine supplements targeting various ailments. [3]

Active Ingredients

The main active polyphenols found within turmeric that are believed to have anti-inflammatory properties are free curcuminoids.

The three main curcuminoids are: curcumin, desmethoxycurcumin, and bisdemethoxycurcumin. [1][2]

As the most bioavailable of the three curcuminoids, curcumin is the best researched. Once digested and circulated in the blood, curcumin is metabolized into curcumin-O-sulfate and curcumin-O-glucuronide. [3]

Research shows that curcumin has extensive biological properties, including: [4]

  • Antiviral
  • Antifungal
  • Antibacterial
  • Antioxidant
  • Anti-inflammatory
  • Pro-apoptotic (promoting controlled cell death)
  • Anti-proliferative

These benefits are attributed to the chemical bonds found within curcumin, including beta-diketone, and unsaturated bonds, methoxy groups, hydroxy groups, and double-conjugated chemical bonds.

Curcumin binds to various targets such as COX-2 and also works indirectly by activating various proteins, enzymes, growth factors, and transcription factors. [3]

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Benefits of Turmeric for Horses

Turmeric is commonly fed to horses to help with a wide range of conditions. A survey of horse owners found that it is chiefly supplemented for osteoarthritis (61%) and lameness issues (31%). [5]

What does the research say about feeding turmeric to your horse? Below are the top 6 benefits of turmeric for horses.

1) Inflammation

Curcumin’s beneficial effects are mainly related to its anti-inflammatory properties which can benefit a variety of physiological processes in the body.

In a study with 11 horses and ponies, supplementation with 10 grams of a blend of green tea and curcumin extract decreased the inflammatory response to a systemic immune challenge. The supplemented equines had lower expression of the pro-inflammatory cytokine interleukin-1 beta after an acute immune challenge with lipopolysaccharide compared to supplemented animals. [18]

Little research has been done to directly compare the effects of nutritional supplements to pharmaceuticals such as NSAIDs. In one study using isolated immune cells from horses, polyphenols including curcumin reduced inflammation as effectively as common NSAIDs. [19]

Therefore, curcumin and other polyphenols may provide an alternative to NSAIDs but more research needs to be done in vivo.

2) Metabolic Health

Metabolic health relies on proper insulin signalling to support blood sugar regulation. Horses that experience insulin resistance and insulin dysregulation have a higher risk of several other health conditions.

Research shows that horses with Equine Metabolic Syndrome (EMS) are more likely to develop painful and debilitating laminitis, as well as other osteoarthritis. EMS is similar to Type 2 Diabetes in humans.

Supplementing with curcumin has been found to support insulin sensitivity and stabilize blood glucose levels in diabetic mice and in vitro laboratory models. In animal models, it has also been shown to decrease inflammation and oxidative stress, which are major contributors to insulin resistance. [6]

The improvement in insulin sensitivity attributed to curcumin may also occur through bile secretion. Bile acids stimulate the secretion of hormones from the intestines, which in turn enhance insulin secretion and sensitivity.

However, horses are continuous bile secretors, unlike mice and humans. For this reason, it is unclear whether turmeric supplementation will have the same effect on equine insulin resistance as seen in mice and laboratory models. [7]

3) Joint Health and Arthritis

Curcumin is a potent anti-inflammatory compound that influences inflammatory pathways associated with osteoarthritis in all mammals.

With an ageing equine population across the U.S. and Europe, there is growing interest in natural anti-inflammatories, to avoid the side effects of commonly prescribed drugs such as NSAIDs. [8]

In horses, curcumin has been found to down-regulate COX-2, an inflammatory mediator in osteoarthritis. Curcumin has also been found to increase interleukin 6, an anti-inflammatory cytokine that plays a role in protecting cartilage integrity. [11]

Cytokines are chemical messengers within the body that increase and decrease levels of inflammation.

Matrix metalloproteases (MMPs) are produced by chondrocytes (cartilage cells) in joints affected with osteoarthritis. MMPs degrade collagen and proteoglycan, which are the building blocks of a healthy joint. [8]

Curcumin suppresses pro-inflammatory cytokine and MMP production by preventing their gene expression. This reduces inflammation and joint degradation. [9][10][11]

Research Results in Horses

In one study, a turmeric supplement containing 150 mg of curcumin was administered to 7 mares with chronic osteoarthritis and 15 foals with osteochondrosis (a developmental orthopedic disorder).

Supplementation decreased pro-inflammatory cytokine production and increased anti-inflammatory cytokine production in all horses. This suggests a potential reduction in joint inflammation, although horse movement was not assessed within this study. [11]

In a small study, three horses with fetlock joint arthritis were supplemented with 50 mg of turmeric (containing 3.19% curcumin) per kg body mass to assess the effects on mobility. Turmeric was supplemented with 15 ml linseed oil and black pepper (six turns on a hind grind dispenser) to increase bioavailability.

A further three horses with fetlock joint arthritis were used as controls and were not supplemented.

The results found that after 10 days of turmeric supplementation, the three horses were more mobile and appeared to have a better mood.

Mobility level and mood were assessed by the same handler before and after turmeric supplementation. The three control horses which were not supplemented with turmeric did not have any alteration in mobility levels or mood. [17]

4) Gastric Ulcer Severity

Turmeric supplementation in horses was originally thought to cause gastric irritation and potentially contribute towards the development of equine gastric ulcer syndrome (EGUS).

However, this theory was disproven by research in twelve Thoroughbred horses. The study showed that feeding turmeric at a high dose of 12 grams per day did not cause EGUS, nor did it worsen ulcers in horses that already had EGUS. [12]

In fact, turmeric may help to lessen the severity of ulceration. It is thought that EGUS affects up to 100% of racing thoroughbreds, and up to 59% of leisure horses.

Squamous ‘splash’ ulcers are most common on the delicate upper lining of the stomach and are associated with dietary issues. Glandular ulcers are less common in horses and their causation is still unclear.

One small study of 10 horses on box rest with a restricted diet, found that turmeric supplementation at 20 grams per day reduced squamous ulceration severity compared to the control group which was not supplemented. Glandular ulcers were not affected by turmeric supplementation.

This suggests that turmeric may help alleviate squamous ulcers as an adjunct therapy with the correct veterinary and nutritional interventions. [13]

5) Respiratory Health

A clinical trial was undertaken to study the effects of inhaled hydro-soluble turmeric for chronic respiratory diseases, such as equine asthma and chronic obstructive pulmonary disease (heaves).

In all eight horses, curcumin treatment decreased proteolytic and oxidative enzyme release and neutrophil degranulation within the lungs.

This suggests that inhaled curcumin may help to reduce chronic inflammation and airway remodelling in horses with chronic respiratory disease. [14]

No curcumin inhaler is currently available for horses, but this may be explored further in the future. It is not clear whether orally ingested curcumin would have the same benefits for respiratory health in horses.

6) Exercise Tolerance

Given the anti-inflammatory effects of curcumin, it is no surprise that it can support exercise tolerance and recovery.

A turmeric supplement containing 1.6 grams of extracted curcumin was administered twice daily to 25 two-year-old racing Thoroughbreds in a clinical trial. The researchers found that the horses had a reduction in proinflammatory cytokine expression.

This reduction in post-exercise inflammation could improve recovery and enhance training outcomes in horses. [15]

How to Use Turmeric in Horses

Dosage

Turmeric is thought to be safe for humans and other mammals, even when supplemented at relatively high daily doses.

In Asian countries where turmeric is consumed in food as a spice, people safely eat up to 2,500 mg of turmeric a day with no adverse effects. Moreover, in a study of 25 people, curcumin was supplemented daily at an extremely high dose of 8000 mg for three months, and no side effects were noted. [8]

A dose of up to 2.4 g per day of turmeric in horses has been suggested as safe. [6]

In research studies, horses have been supplemented with 12 – 20 g per day of turmeric for short periods of time. without adverse effects.

Absorption and Bioavailability

Bioavailability is a pharmacological term for how much of a drug or chemical is absorbed into the bloodstream and reaches its therapeutic target in the body.

The main active compound curcumin accounts for approximately 2% of turmeric root, meaning that a significant amount of raw turmeric must be consumed in order to ingest a therapeutic dosage.

Curcumin also has poor water solubility, poor absorption into the blood, and rapid metabolism and elimination. It has limited oral bioavailability of approximately 1%. [16]

To increase the bioavailability of curcumin, turmeric is often supplemented with oil and piperine. Curcumin is fat-soluble (dissolves better in oil than water), so feeding it with a fat source can help to increase absorption. 

Piperine is the active medicinal ingredient in freshly ground pepper. It improves the uptake of curcumin from the digestive tract and helps slow down metabolism and elimination of this compound. [16]

The effect of these supplement combinations on curcumin bioavailability appears to be species-specific however, and no horse-specific research has been undertaken. In human research, the addition of piperine increased curcumin bioavailability by 2000%, whereas only a 154% increase was seen in rats. [8]

Further research is required to determine whether oil and piperine significantly increase curcumin bioavailability in horses.

Safety and Side Effects

Turmeric supplements are generally well-tolerated in horses, based on anecdotal reports. Typical feeding rates are unlikely to have negative side effects.

However, excessive dosages humans and canines has been linked to some potential side effects, including: [8]

  • Anemia – Curcumin is an iron chelator. However, anemia is very rare in horses and iron intake is typically in excess of requirements
  • Bioaccumulation of prescribed drugs, such as NSAIDs, morphine, and acetaminophen. Curcumin inhibits some drug-metabolizing enzymes
  • Hindgut dysbiosis – in other species it may cause loose feces through reducing desirable gut microbes
  • Increased risk of kidney stones

These effects have not been observed in horses, even in studies providing 20 grams per day of turmeric. [13]

Summary

Though the benefits of turmeric are well-documented in humans and other species, there is limited research into the effects of this herb on horses.

The research conducted to date has primarily focused on anti-inflammatory benefits for conditions associated with inflammation, such as osteoarthritis and respiratory disorders. The studies available are relatively small scale and there is still much to learn.

Based on available research data, turmeric supplementation in horses may:

While turmeric appears safe, care must be taken to monitor horses supplemented with novel nutraceuticals for any change in behaviour, appetite, fecal output, weight and body condition. Changes could indicate side effects and a veterinarian or qualified equine nutritionist should be consulted.

For individualized advice on your horse’s feeding and supplementation plan, submit their diet online for evaluation by our equine nutritionists.

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References

  1. Liu, Y. et al. Simultaneous quantification of free curcuminoids and their metabolites in equine plasma by LC-ESI–MS/MS.. J Pharm Biomed An. 2018. View Summary
  2. Aggarwal, B.B. and Sung, B. Pharmacological basis for the role of curcumin in chronic diseases: an age-old spice with modern targets. Trends Pharm Sci. 2009.
  3. Vareed, S.K. et al. Pharmacokinetics of curcumin conjugate metabolites in healthy human subjects. Cancer Epi Biomarkers. 2008.
  4. Aggarwal, B.B. et al. The molecular targets and therapeutic uses of curcumin in health and disease. IN: Curcumin: The Indian solid gold. . Springer Publishing. 2007.
  5. Marlin, D. et al. Owner-reported experiences of feeding turmeric to horses. J Equine Vet Sci. 2017.
  6. Weisberg, S.P. et al. Dietary curcumin significantly improves obesity-associated inflammation and diabetes in mouse models of diabesity. Endocrinology. 2008.
  7. Tinworth, K.D. et al. Potential treatments for insulin resistance in the horse: A comparative multi-species review. Vet J. 2010. View Summary
  8. Dejonckheere, V. Turmeric for Osteoarthritis in Veterinary Medicine, a Review.. Proceedings. 2016.
  9. Peddada, K.V. et al. Role of curcumin in common musculoskeletal disorders: a review of current laboratory, translational, and clinical data. Orthop Surg. 2015.
  10. Moore, T.L. et al. Oral curcumin supplementation improves fine motor function in the middle-aged rhesus monkey. Somatosens Mot Res. 2019.
  11. Farinacci, M. et al. Dietary administration of curcumin modifies transcriptional profile of genes involved in inflammatory cascade in horse leukocytes. Ital J Anim Sci. 2009.
  12. Blanc, M. et al. Effects of supplements containing turmeric and devil’s claw on equine gastric ulcer scores and gastric juice pH. Equine Vet Edu. 2021.
  13. Fletcher, S.P.S. and Gough, S.L. Pre-Treatment with Turmeric (C. Xanthorrhiza) Reduces the Severity of Squamous Gastric Ulceration in Feed Restricted Horses. J Anim Sci Res. 2019.
  14. Sandersen, C. et al. Effect of inhaled hydrosoluble curcumin on inflammatory markers in broncho-alveolar lavage fluid of horses with LPS-induced lung neutrophilia. Multidiscip Respir Med. 2015. View Summary
  15. Horohov, D.W. et al. The effect of exercise and nutritional supplementation on proinflammatory cytokine expression in young racehorses during training. J Equine Vet Sci. 2012.
  16. Anand, P. et al. Bioavailability of curcumin: problems and promises. Mol Pharm. 2007.
  17. Eyles-Owen, S. Dietary turmeric reduces inflammation and improves mood and mobility in horses with fetlock joint inflammation. Young Sci J. 2021.
  18. Starzonek, J. et al. Effects of a blend of green tea and curcuma extract supplementation on lipopolysaccharide-induced inflammation in horses and ponies. Peer J. 2019. View Summary
  19. Siard, M.H. et al. Effects of polyphenols including curcuminoids, resveratrol, quercetin, pterostilbene, and hydroxypterostilbene on lymphocyte pro-inflammatory cytokine production of senior horses in vitro. Vet Immunol Immunopathol. 2016. View Summary