June 01, 2020
Antioxidants and Their Role in Pet Health
by Dr. Cayla Iske, PhD
Antioxidants have been a buzzword in the human health world for quite some time now. For years, human doctors and nutritionists have been touting the antioxidative benefits of a diet rich in leafy greens and veggies; More recently, antioxidants have gained popularity in the pet food aisle as well. But, what exactly are antioxidants and how are they beneficial to our pets (and us)?
To really understand why antioxidants are beneficial we must first talk about oxidative stress. Oxidative stress occurs when there are too many free radicals in the body without adequate antioxidants to neutralize them. Free radicals are molecules that contain an unpaired electron which causes them to react with other molecules because they are unstable. Free radicals can be produced due to a myriad of factors - from inhalation of polluted air to food digestion and metabolism to simply stress. These free radicals can damage and alter proteins, deoxyribonucleic acid (DNA), and lipids in the body, all potentially leading to serious health issues. Heart disease, diabetes, cancer, and neurodegenerative diseases are just a few serious conditions that have been linked with oxidative stress.
Animals (humans included) have some built-in antioxidant systems to help neutralize free radicals before they cause damage, but in some cases, especially with chronic disease and the ongoing aging process, the body’s own defense is not enough. Animals exposed to higher levels of pollution, those with chronic health issues, animals not consuming an appropriate diet, or older animals are all at higher risk of oxidative stress due to higher rates of free radical production and/or suppressed antioxidant systems.
When the body’s own oxidative stress defense mechanisms fail, or can’t adequately offset free radicals, dietary antioxidants can come to the rescue. Many high-quality, pelleted fortified foods contain antioxidants, often in the form of common vitamins such as vitamins E and C. These vitamins are required by animals for normal physiological functions, but also function as antioxidants in times of oxidative stress. Pelleted foods also bring natural antioxidants from ingredients such as grains, grasses, and herbs. For exotic companion mammals, greens and veggies have the highest potential to supply animals with antioxidants. Many greens and veggies contain phytonutrients called flavonoids which, along with carotenoids, give them their vibrant colors. Flavonoids, including anthocyanin, lutein, zeaxanthin, and quercetin, and carotenoids such as beta carotene are powerful antioxidants and are a big part of the reason vegetables provide so many health benefits to animals and humans alike.
Dietary antioxidants, whether vitamins, flavonoids, carotenoids or other classes, provide a large diversity of known, and many likely yet undiscovered, health benefits by helping to combat or avoid oxidative stress. The exact method of mitigation varies by specific compound but, in general, antioxidants either inhibit the production of free radicals in the first place or directly neutralize existing free radicals. To reduce free radical production, antioxidants can inhibit enzymes that create free radicals in their reactions or can bind molecules that tend to lead to free radical production down the road. When antioxidants neutralize free radicals, they essentially sacrifice themselves, so the reactive molecule doesn’t instead damage important DNA, proteins, or lipids in the body. Consumption of many different types of antioxidants through a complete and varied diet can help to provide a more robust and complete defense system from oxidative stress and the damage it can cause.
Just as diet can help mitigate oxidative stress, it can also exacerbate it. It is, therefore, important to feed our pets a nutritionally complete and balanced diet including a diversity of free choice hays, a controlled amount of uniform pellets, dark leafy greens, and appropriate vegetables. It may sound like more greens and veggies are better, but recommended feeding guidelines (including types and amounts) are important to follow in order to ensure other key nutrient requirements (such as fiber) are always met and gastrointestinal upset is avoided. Feeding recommendations for rabbits, guinea pigs, hamsters and gerbils, and rats can be found in our previously published blogs.
Better with Age
In addition to many diseases, the natural aging process also has much to do with oxidative stress. As the body ages, its processes become less efficient and generates more free radicals. The body’s natural mechanisms designed to repair ongoing damage from oxidative stress also wane with age. These two factors contribute to more oxidative damage, resulting in higher rates of disease as well as physical signs of aging. The accumulation of oxidative damage over time is a popular theory for why animals and humans age.
Flavonoids and other classes of antioxidants can also help reduce inflammation and inflammatory driven diseases such as inflammatory bowel disease, dermatitis, and arthritis. While antioxidants are beneficial for animals of all ages, they are clearly most essential in elderly and aging pets to help mitigate common ailments associated with the aging process. Feeding a nutritionally correct diet which includes a diversity of appropriate greens and veggies throughout your fur baby’s life will help ensure they continue to devour them well in their golden years, yielding maximum antioxidant benefits. In general, the darker the greens, the more antioxidant punch they pack and leafy greens tend to be a better source of antioxidants than veggies.
In previous posts we have highlighted essential contributions of greens and veggies, as well as plant-based ingredients, including hydration, vitamins, and minerals and even the importance for nutritional and behavioral enrichment. In this discussion, we took a deeper look to see the benefits of these foods go even farther to provide antioxidant properties and protection against oxidative stress. These nutrients can provide many benefits to your animal to keep them happy and healthy for years to come.