8. Antioxidants: Department of Defense

What are the antioxidants in the horse's body that can control this continual onslaught of oxidation? Some of the horse's antioxidant molecules are made within the body, while others are supplied by the diet. Both types are needed to manage free radical interactions and keep them from inhibiting metabolism or causing lasting damage. The antioxidants include vitamin C, vitamin E, coenzyme Q10, lipoic acid, carotenoids, enzymes derived from B complex vitamins, superoxide dismutase (SOD), catalase, glutathione (GSH), and glutathione peroxidase (GPX), to name a few. Some other molecules play transient roles as antioxidants in specific situations.

Early antioxidant research focused mainly on the dietary antioxidants. The effects of molecules like vitamin C, vitamin E, and beta carotene were measured in the nutrition of humans and animals. Antioxidants that could not be provided in the diet did not gain as much attention as these vitamin antioxidants.

Nowadays, researchers explore the inner workings of the cells in far greater detail, and monitor the level and nature of antioxidant protection at each step. Today's scientists are finding that the most important single factor for radical control inside the cells is GSH.³⁰