Phytonutrients are a relatively new class of natural compounds showing tremendous value in controlling inflammation and its negative effect on health. Hundreds of plants naturally produce these compounds, known as flavonoids, carotenoids, polyphenolics, and anthocyanins, to protect themselves from oxidative damage. These protective substances are antioxidants that give plants and fruits their color. Citrus fruits, grapes, berries, and green, red, and yellow vegetables are all examples of antioxidant-rich foods.

As an antioxidant, phytonutrients have the ability to quench free radicals, which are molecules with an unpaired electron that randomly pull electrons from other molecules. Although the body produces free radicals as part of normal metabolic activity, excessive levels of free radicals create an adverse cycle of cellular events, which may lead to cell damage (aging and disease) or destruction.

Exposure that can contribute to free radical stress can come from the environment, such as air pollution, toxic metals, herbicides and pesticides. The vitamins C, E, and beta carotene are effective free radical scavengers. The minerals selenium, copper, zinc, and manganese also produce antioxidant enzymes in the body.

Equine diets typically lack these fresh antioxidant compounds. Rarely do most horses have an ample supply of fresh green pastures. Most are fed dried hay and grains. In fact, many horse feeds are highly processed and refined, which further reduces the antioxidants that occur naturally in their native diet