Edmund R. Dorosz, BSA, DVM
When metals are exposed to air and moisture they rust. The oxygen from this exposure causes them to oxidize. If foods are exposed to oxygen as well, they go rancid. When this happens to living tissues we witness aging, disease, inflammation and cancer. In other words this process not only occurs to metals and foods but also to the tissues within living bodies. To prevent foods and tissues from oxidizing, Nature has provided the antioxidants. Antioxidants prevent oxidation or the "rusting" of foods and living tissues.
Vitamin E is one of Nature's powerful antioxidants. Vitamin E or alpha tocopherol, is a fat and oil soluble vitamin belonging to the group of compounds, the tocopherols that can prevent oxidation. What is an antioxidant? First we must discuss oxidation which simply is combining with oxygen. The rusting of metal and the brown spoilage of fruit or butter going rancid are examples of oxidation, combining with oxygen. Spoilage in other words. Nature's natural recycling process by decomposing materials to their basic elements.
Modern medicine is now saying that perhaps some of our modern diseases are due to oxidation - we're slowly rusting out. An antioxidants is a compound that prevents oxidation.
Oxygen is essential for basic cell functions in dogs, cats, humans, and most animals, as we all know. However, oxygen can also produce toxic substances and these highly reactive substances, called "free radicals" can combine with other molecules in the body, such as heavy metals or other foreign chemicals resulting in internal cellular destruction. These free radicals are unstable compounds with an unpaired or extra electron in their chemical make-up looking for an electron to become stable. The antioxidant offers this electron that the free radical is looking for, rendering it stable, preventing it from becoming destructive to living cells.
Drs. Stephen Davies and Alan Stewart in their book Nutritional Medicine, Avon Books, state "It is now becoming evident that free radical reactions in mammalian systems are probably responsible for such diverse physiological processes as inflammation, aging, drug induced damage, degenerative arthritis, alterations in immunity, cancer and cardiovascular disease."
Antioxidants such as vitamin E counter this process. These substances protect the cells against the oxidation process. Some of the other common antioxidants that we know are vitamin A, vitamin C, selenium, some herbs and several enzymes found within the living body. These substances plus others that are being discovered can, for example prevent fruit from spoiling or fats from going rancid. More important however is the protection that these antioxidants provide inside the body.
Unsaturated fatty acids in foods and the lipid (fat) membranes of body cells are very vulnerable to oxidative damage. Antioxidants such as vitamin E interrupts the oxidation of these membranes by giving electrons to the free radicals before they can cause damage.
A recent study done at Colorado State University shows when 80 beef steers were supplemented with 500 units of vitamin E per day for 123 days, it had a remarkable effect on meat shelf life. For example, the number of T bone steaks that had to be "marked down" for immediate sale was reduced by 83%. In other words the meat from the steers fed vitamin E was prevented from spoiling as quickly as meat from steers that were not supplemented with vitamin E. More studies are on going.
I believe that this demonstrates the effects of vitamin E as a potent antioxidant within the animals' bodies. Is this also happening within our bodies and the bodies of our pet animals when they eat foods containing antioxidants such as vitamin E. Is the rusting out process slowed down?
Manufacturers of dry pet foods add antioxidants to their pet foods to extent shelf life and prevent spoilage. Synthetic antioxidants such as ethoxyquin, BHA and BHT are being used to prevent the fat in pet foods from going rancid in storage and on exposure to air and moisture when the bags are opened.
Controversy has arisen over the years with regard to what these synthetic fat preservatives are doing to the animals that eat them over an extended period of time, in other words what are the long term effects of the synthetic antioxidants on the fat cells within the body of the cat or dog? Some pet food manufacturers are now using antioxidants such as vitamin E (alpha tocopherol) and vitamin C (ascorbic acid and/or sodium ascobate) to preserve the fats in their dry pet foods and are calling these products "Natural Cat or Dog Food".
If we raise the question, why are we seeing an increase in chronic diseases especially those associated with the immune system ? The answer may lie with excessive oxidation and free radicals. Excessive oxidation or oxidative stress can develop from many sources. Nutritional deficiencies, disease, drugs, stress and heavy metal pollutants from our pet's environment or the environment of the food sources can increase the amounts of free radicals in the pet's body. Combined with a diet of refined or processed foods which have removed many of Nature's known and unknown antioxidants that would normally offer protection. This then may be the answer to why we are seeing more diseases such as cancer, allergies and hereditary problems in our pet populations today.
Environmental poisons such as insecticides, herbicides, preservatives, taste enhancers and color additives as well as polluted air and water are increasing the load of destructive free radicals that our dog's and cat's bodies must deal with.
To help our animals deal with this, the argument can become quite convincing for feeding fresh foods and supplementing with vitamins and minerals. The particular substances that we know that offer antioxidant protection for the cells are vitamins A, C and E, selenium, zinc, manganese and copper.
Vitamin E combined with its helper selenium are two such antioxidants. Vitamin E is a fat and oil soluble vitamin made by Nature in a variety of plants. Foods sources that are rich in tocopherols include wheat germ and the oil of corn, cottonseed, soybean and sunflower. Most animal sources have limited amounts of vitamin E however the vitamin is present in egg yolks and liver.
Antioxidants are getting a lot of press lately with regard to their health benefits as well as new sources being discovered and researched. For example, plants such as garlic and sprouts, the herbs thyme, ginko, milk thistle and pycnogenenol from pine bark contain antioxidants. We are going to hear more in the future about antioxidants and how free radicals cause disease.
Vitamin E, as an antioxidant, is being utilized more and more in our everyday lives. It is being used as a supplement to prevent the destructive intentions of free radicals and as a preservative for foods by extending shelf life both by adding it to the food or by feeding it to meat producing animals. The "anti-rust" vitamin is becoming quite popular.
About Edmund R. Dorosz, BSA, DVM
NetPets® Main Page
The Dog Center