Training and ageing wear on a horse's skeletal system and joints. Training-related strain involves multiple changes in the physiology of different organs and tissues. Hard or prolonged training can exceed the body's antioxidant defence, which includes, among others, vitamins E and C, and this can result in tissue damage of varying degrees. For a horse's joints—or an athletic dog's joints—to remain healthy and functional despite the stress caused by exercise, they need nutrients that maintain articular cartilage and synovial fluid and that counter the oxygen radicals produced by exertion. According to studies, strengthening the body's own antioxidant defence may reduce exercise-induced damage.
Antioxidants
Vitamin E acts in the body as an antioxidant that protects cells from the harmful effects of free radicals (including, for example, lactic acids produced by physical performance). Vitamin C is also a well-known antioxidant that prevents cellular oxidation and fights free-radical-related damage within cells. In addition to their antioxidant properties, vitamins C and E play an important role in immune defence, i.e., resistance. Vitamin C also supports the body's own collagen production, which is important for the durability of joints and tendons.
Methylsulfonylmethane, better known as MSM, is a naturally occurring sulfur compound that also has well-known antioxidant properties. Sulfur functions in the body, among other things, as a building block for joint surfaces, cartilage, and connective tissues. According to studies, MSM helps support joint function and, when needed, may help ease inflammatory symptoms related to exertion and reduce muscle stiffness.
Training-related load causes changes in several organs and tissues in the horse or dog, and this process of change may be driven by oxidative damage caused by free radicals and inflammatory mediators.
MSM & vitamin C study in showjumping horses
In a study conducted on showjumping horses, researchers investigated whether supplementing MSM and vitamin C could alleviate exercise-induced oxidative stress in horses participating in jumping competitions.
The study included 24 horses. The horses were divided into three groups: one group received a placebo, a second group received MSM at 8 mg/kg, and a third group received MSM at 8 mg/kg plus vitamin C at 5 mg/kg. Blood samples were taken from the horses before training, during exertion, and weekly after the final competition. From the blood tests, plasma levels were determined for, among other things, nitric oxide, carbon monoxide, lipid hydroperoxides, and antioxidant enzymes—glutathione peroxidase, glutathione transferase, and glutathione reductase.
The blood results showed that competition significantly increased the body's lipid peroxidation, nitric oxide, and carbon monoxide, all of which have tissue-damaging properties. At the same time, it was also observed that glutathione and antioxidant enzyme activity decreased. Glutathione is an important antioxidant molecule that plays an essential role in eliminating certain toxins from the body. Selenium functions in the body, among other things, in fat metabolism as a structural component of the glutathione peroxidase enzyme. In addition, selenium binds toxic heavy metals such as mercury, lead, and cadmium.
The study found that giving MSM significantly reduced all of these exercise-related, body-burdening changes. The study also showed that vitamin C enhanced MSM's protective effect against exercise-induced oxidative stress. From this, it can be concluded that MSM and vitamin C work together synergistically to protect cells from oxidative damage.
The results indicated that intense jumping exercise can cause harmful effects on the horse's tissues, likely due to an increase in oxidative damage and pro-inflammatory molecules. The study also suggests that MSM may have a protective effect against oxidative and inflammatory, exertion-related injuries. Therefore, for sport horses (and dogs), it can be justified to provide MSM as well as a vitamin C supplement to help counter tissue damage.
