by Casie Bazay

Review of antioxidants for horses: Astaxanthin

Review of antioxidants for horses: Astaxanthin

Published: January 2021 | Updated: May 2024

Oxidation is a natural process that occurs when oxygen is combined with various other elements in the body during metabolism. It happens to humans, and it happens to our horses and other animals as well. 

However, the rate of oxidation will depend on the activity of the animal. At rest, the rate of oxidation is lowest, but during exercise, stress, pregnancy, or lactation, it’s normal for the rate of oxidation to increase, sometimes significantly. 

When these rates increase, this is known as oxidative stress. When this occurs, the amount of free radicals or reactive oxygen species (ROS) in the body increases. ROS are damaged cells that are missing a critical molecule, and as a result of this missing molecule, go on a “rampage” in the body in an attempt to pair with another molecule. 

In fact, an overabundance of ROS will damage healthy cell membranes, leading to decreased immune function, illness, and/or nervous system dysfunction within the animal.  

This is where antioxidants, substances such as vitamins, minerals, and plant extracts, that slow and prevent ROS damage, come into play. In fact, antioxidants are a crucial part of every horse’s diet. 

You might be wondering how you can ensure that your horse is getting plenty of antioxidants, and the good news is that if your horse is kept on green pasture, he is likely getting plenty of these nutrients. 

However, many horses do not (or cannot) have access to green pasture, and unfortunately, the process of drying and curing hay destroys most of the antioxidants naturally present within plants.  

Additionally, some horses need more antioxidant support than what green pasture can provide, such as in these cases:

  • Horses in moderate to heavy work;
  • Older horses;
  • Growing horses;
  • Horses with muscle disorders such as tying up or polysaccharide storage myopathy (PSSM);
  • Ill, injured, or immune-compromised horses; and
  • Horses with allergies.

For working horses, antioxidant supplementation trials have shown that exercise-induced muscle damage can be partially prevented (3). 

Vitamin E and selenium supplements, as well as Vitamin C are often popular choices for owners of performance and working horses. But, are these the best options when it comes to antioxidant supplementation? Research suggests that they may not be. 

What is the Best Equine Antioxidant Supplement?

Several well-established equine antioxidants include vitamins A, E, and C, as well as the trace minerals zinc, copper, and selenium. However, new research shows that one particular antioxidant known as astaxanthin, derived from the microalgae, Haematococcus pluvialis or Phaffia rhodozyma yeast, can be a game changer when it comes to horse health and performance. 

Astaxanthin is a carotenoid, a special type of antioxidant which gives salmon, lobsters, and even flamingos their red or pinkish hue (due to the fact that they feed on the microalgae). Carotenoids have attracted a great deal of interest in recent decades due to their potent biological activities, including antioxidant, antiproliferative, anti-inflammatory, and anti-aging properties. 

Similar to a beta-carotene (which converts into vitamin A), astaxanthin is reported to have strong activity related to inhibiting oxidation of polyunsaturated fatty acids.  

And, when compared to other antioxidants, astaxanthin has the ability to deactivate ROS at the following rates: 

  • 6,000 times greater than vitamin C
  • 800 times greater than coenzyme Q10
  • 560 times greater than catechin
  • 75 times greater than alpha-lipoic acid

All of this research indicates that astaxanthin is one of the strongest antioxidants available. 

It has shown other health benefits in humans as well, such as lowering oxidative stress in overweight people and smokers. Fortunately, this antioxidant has also shown to have excellent safety and tolerability in both people and animals. 

Astaxanthin and Equine Metabolic Syndrome

New research in horses points to astaxanthin’s ability to help regulate EMS as well. Metabolic syndrome encompasses several endocrine disorders such as insulin resistance, diabetes, obesity, and inflammation, which affects both humans and animals. 

EMS is characterized by regional adiposity (fat tissue) in the neck, tail head, and above the eye. This condition is associated with insulin resistance and laminitis. Interestingly enough, EMS can also affect sport horses, despite regular exercise and a good diet.

However, research shows that astaxanthin significantly reduced cell death, alleviated oxidative stress, and restored mitochondrial oxidative phosphorylation in horses with EMS. 

Therefore, scientists believe that astaxanthin can improve the overall metabolic status of horses suffering from EMS and play a role in both prevention and treatment of this disease. 

Astaxanthin and Exercise-Induced Oxidative Stress

Research shows that astaxanthin can help ward off muscle problems in horses, such as instances of tying up. However, researchers are continuing to study the effects of this antioxidant when it comes to muscle health. 

It’s well known that heavy work loads can increase rates of oxidative stress and that this can lead to muscle breakdown. In fact, researchers believe that exercise-induced oxidative stress contributes to accelerated muscle fatigue as well as muscle damage. 

Fortunately, astaxanthin can help to combat this issue. And though it has proven to be a powerful antioxidant all on its own, researchers have learned that its effects are even further enhanced when astaxanthin is given in conjunction with the amino acid derivative, L-carnitine

L-carnitine is required for fatty acid transport within the body and is believed to improve exercise performance through enhanced muscle fatty acid oxidation, altered glucose homeostasis, enhanced acylcarnitine production, and altered muscle fatigue resistance. 

In a study evaluating the efficacy of a dietary supplement containing both astaxanthin and L-carnitine, researchers found that the two ingredients decreased serum marker levels of exercise-induced muscle damage in Thoroughbred horses in training. 

In addition, the researchers found that the incidence rate of clinical signs related to exercise-induced muscle damage were significantly decreased by daily supplementation of astaxanthin and L-carnitine (3).  

Because astaxanthin and L-carnitine, together, have shown measurable effects when it comes to reducing exercise-induced muscle damage, FullBucket includes them as the primary ingredients in Medical Muscle, the ultimate recovery and antioxidant supplement for horses. 

If you want to fight oxidative stress and keep your performance horse on the right track, Medical Muscle is most definitely the way to go. Keep in mind that this supplement can have benefits for horses with EMS as well. 

Read More:

  1. Could a Supplement Ease the Effects of Tying Up?
  2. Astaxanthin, Cell Membrane Nutrient
  3. Effects of Daily Astaxanthin and L-Carnitine Supplementation for Exercise-Induced Muscle Damage in Training Thoroughbred Horses
  4. Astaxanthin Carotenoid Modulates Oxidative Stress in Equine Metabolic Syndrome Affected Horses

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