Picture of Dr Anuska Viljoen

Dr Anuska Viljoen


What are Antioxidants and why do we need them?

During normal cellular metabolism and function, the body produces unstable oxygen by products known as “oxygen free radicals” in a very similar way to rust forming on exposed oxidising metals.

These unstable free radicals attack adjacent molecules and thus cause cellular tissue, membrane and DNA damage, and is responsible for the general ageing process or any degenerative disease. An estimated number of radical “hits” on each cell of the body per day is around the 10,000 mark. This process is accelerated when we are exposed to polluted or toxic substances that we breathe in or eat. Lucky for us, antioxidants are substances that mop up free radicals. By protecting cells against free radical damage, anti-oxidants help to prevent disease, slow down the ageing process, and improve the function of the immune system.

Antioxidant enzymes in our body

Superoxide Dismutase (SOD), Catalase, Glutathion Peroxidase and Methionine Reductase, are the bodies major enzymes for keeping the oxygen radicals under control. These enzymes require other minerals and elements which act as co-factors to function. Many of their trace elements and minerals are deficient in our normal diet and we have to therefore supplement them for optimal enzyme function. These are the substances we generally think of as anti-oxidants, such as Vit E, C, Beta-carotene, lycopene, xanthene and other carotenoids, Coenzyme Q, Picnogenol and other turpenoils, Glutathion, Uric Acid, Selenium, Zinc, Copper, Manganese and Iron. Many herbs and plants contain large numbers of these co-factors. Foods especially rich in these substances are, sprouts of any kind, soy beans, green, white and rooibos tea, most pigmented edible berries, herbs and spices such as rosemary, garlic, turmeric, ginger etc.

Antioxidant drains

Any form of bodily stress or physiological disturbance will increase the number of free radicals formed. This will use up the bodies antioxidant resources and if not regularly replenished, radicals that are formed and not neutralised will start a reign of uncontrolled damage and so the vicious circle of decompensation occurs. The most common factors that our pets and ourselves are exposed to is: smoking, environmental pollutants, rancid or overheated fats mainly in processed foods, infection, inflammation, tissue trauma, pharmaceutical, preservative and recreational drugs, UV light exposure and radiation (even from your microwave).

Optimal amounts in daily intake

The optimal amount required by the body obviously depends on each individual’s habits, environment, level of fitness and exercise , body weight, body type and breed (or family tendencies to certain disease) and of course age. As the body gets older, the ability to regenerate cells and to cope with free radicals diminishes. Does the average pet food contain adequate levels of antioxidants to maintain the average animal’s health? Some are better than others! The pet food industry is only interested in ensuring enough nutrients are incorporated into the diets to prevent deficiencies and not specifically for optimum health. The antioxidants that are included in processed pet food is usually of synthetic nature to prevent the food from going rancid as it has such a long shelf life.

Synthetic and Natural Antioxidants

Synthetic antioxidants like BHA and BHT have been used as preservatives in human and animal foods for more than 30 years. Many pet food manufacturers prefer to use ethoxyquin today however, because of its excellent antioxidant qualities, high stability and reputed safety. But significant ongoing controversy surrounds issues related to its safety when fed at permitted amounts in dog and cat foods over a period of time. The same antioxidants have been linked to inducing or promoting a wide variety of cancers and degenerative diseases. Some anti-oxidants can become pro-oxidant if denatured or stale. This will accelerate the free radical oxidising effect.

Naturally occurring antioxidants (vitamin E and C) are also used in pet foods, and have become more popular in response to consumer and professional queries about the chronic effects of feeding synthetic chemical antioxidants to pets. While they are somewhat less effective and more expensive than the synthetic antioxidants, their safety outweighs these drawbacks. It should be noted that some pet foods devoid of synthetic antioxidants added at the time of processing might contain ingredients (such as animal tallow or other fats and oils) that are preserved with antioxidants (possibly synthetic). Therefore know and trust your source.

Should I be supplementing my dogs diet?

Generally for the average situation and on the average diet used today I would say yes! However if your dog is on a freshly made, or frozen uncooked balanced diet with adequate amounts of antioxidant packed vegetables and enzymes, then the answer will be only in situations of particular need such as stress, injury or illness or old age. I hope to tackle specific illnesses, stresses or diseases and which supplements would help the most in these conditions over the next issues in future. For the mean time, there is absolutely no harm in using a general mixed antioxidant to supplement your pets diets if they fall into any category of need above. Don’t forget, what is good for your pet, is often good for you too, so consult a nutritionist, or ask your doctor if you are concerned about your own health status.

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