Free Radicals
Free radicals are produced as the result of normal body processes and due to normal environmental conditions. Most of the time, they are unable to cause lots of damage as the body has its own defence against them, in the form of antioxidants.

However. there are times when these free radicals overwhelm the defence mechanisms and cause damage. This is known as oxidative stress and has effects in the in ageing and disease processes. Injury, stress, competition, travelling  exposure to certain environmental substances such as pollutants or allergens, can contribute to free radical production and oxidative stress. However, it is increasingly thought that nutrition may play an important part in helping to protect against this damage.

Antioxidants, otherwise known as ‘free-radical scavengers’, are the body’s natural defence against free radical damage. Diets rich in polyunsaturated oils increase the requirement for antioxidants, especially vitamin E. More importantly, poor nutrition may reduce the horse’s ability to mount a sufficient antioxidant defence. Oxidative stress may also result following exposure to certain environmental factors such as UV light, radiation, pollution, allergens, physical injury and exercise. Some nutrients and dietary components have antioxidant properties which may offer a protective role against a number of diseases. Work has suggested that a mixture of antioxidants may be more beneficial than a single antioxidant in helping to support antioxidant defences
 

Vitamin C is water soluble and is believed to be one of the most important antioxidants in extra-cellular fluids. Unlike humans, primates and guinea pigs, the horse is able to synthesise it’s own supply
 

Vitamin E is a collective name for a number of biologically similar compounds which share the same activity. A dietary source of vitamin E is essential as unlike vitamin C, it cannot be synthesised. Vitamin E is fat soluble and is the major antioxidant involved in maintaining cell membrane integrity. Dietary sources of vitamin B in equine diets include cereal grains and alfalfa.
 

Herbs and spices are very valuable sources of antioxidants. At least 30 food spices and herbs have been shown to possess antioxidant properties. For example eugenol is the active antioxidant compound in garlic and flavenoids are found in rosemary