The main reason your dog’s food can stay sitting on the store shelves, and then be stored in your pantry for a while longer, is that the food is kept preserved with antioxidants and other very necessary ingredients. Antioxidants are substances that provide health benefits and prevent ingredients in the food from breaking down or spoiling (oxidation). They are very important to keep your dog’s food tasting good and to help maintain its nutrients.
Oxidation is the process that occurs when foods are exposed to oxygen. Naturally, over time the oxygen will lead to a break down in the nutrients and fats in a food and cause everything from discoloration to rancidity. An antioxidant works to block or slow down the rate at which oxygen causes damage. Antioxidants are added to dog foods during processing to extend the shelf life of the final product.
There are numerous health benefits provided by antioxidants. Antioxidants protect the body’s cells from damage and strengthen the immune system. Every day, the body is exposed to the destructive effects of free radicals. Antioxidants prevent cell damage and allow the immune system to function without interference from free radicals. In young animals, antioxidants boost the developing immune system. In older animals, oxidative cell damage may be slowed by antioxidants — providing a longer, healthier lifespan.
There are two types of antioxidants used in dog foods — natural and synthetic. Natural antioxidants include vitamins C, E, citric acid, and some herbal sources like rosemary. Vitamin C can be taken from common fruits and vegetables like cranberries, apples, tomatoes, blueberries, and more. Vitamin E is commonly listed as “mixed tocopherols” on the pet food ingredient list. Citric acids are taken from various citrus fruits like oranges, lemons, and limes.
Common synthetic antioxidants (created in a laboratory) include BHA, BHT, and ethoxyquin. BHA and BHT are chemically similar to vitamin E and are often used in combination in dog foods. These two antioxidants are stable at high temperatures and used often because they are more cost effective than natural antioxidants. Ethoxyquin has been questioned in the past, but is considered to be very effective, with little concern about side effects, at the FDA-approved levels.
Keep in mind that pet food companies are required to list any antioxidants used along with their common names. You will also see a notation that the ingredient is used as a preservative. Store foods in a cool, dry place, preferably in an airtight container, out of the light. Once opened, a food preserved with only natural antioxidants will lose its freshness sooner, so you may wish to purchase smaller packages of these foods.