What do antioxidants do? —chronic low-level inflammation is at the root of most diseases: heart disease, cancer, diabetes, renal issues, and allergies. Low level inflammation is “silent” and destructive so that the danger is insidious and may go undetected for years. Our daily bodily functions involve tissue injury, release of free radicals that go on to create inflammation, and infection by viruses, bacteria, or fungi that constitute an ongoing accumulation of free radicals. Free radicals work at the cellular level affecting the regulation of immunity. Antioxidants, the most common of which being omega-3 fatty acids, most often in the form of fish oil, actively provide protection against free radical destruction. Other antioxidants include: Vitamin C, Vitamin E, alpha lipoic acid, green-lipped mussel, milk thistle, and palmitoylethanolamide.
How they work–antioxidants such as essential fatty acids (EFA) are used by enzymes to form mediators of inflammation (prostaglandins and leukotrienes). Prostaglandins and leukotrienes derived from omega-6 (arachidonic acid-AA) are pro-inflammatory whereas those derived from omega-3 (eicosapentanoic-EPA and docosahexaenoic acid-DHA) result in a reduced inflammatory response which stimulates the immune system to work better.
Antioxidants treat inflammation by stabilizing cell membranes, steering the inflammatory cascade into making less inflammatory mediators, and influencing gene expression. Omega-3 fatty acids such as DHA and EPA are essential for maintenance of numerous organ functions. These functions include skin, kidney, heart, bone, and gastrointestinal health, brain tissue, cognition, immunity, and inflammation. Cancer and diabetes have also found a role in altered antioxidant metabolism.
Omega-3 fatty acids are helpful in heart disease in dogs and cats to reduce inflammation and protect against arrhythmias. They are essential for normal development and maintenance of brain/nervous system and eye (retinal) tissue. Along with omega-6 fatty acids they help normalize the defective skin barrier that is present in atopic dermatitis in dogs and cats, aid in seborrhea (dry skin), and reduce itching associated with atopy (allergy). In osteoarthritis, omega-3 fatty acids control the production of pro-inflammatory mediators and help prevent joint destruction. In kidney disease, they reduce the production of pro-inflammatory eicosanoids and prevent hypertension in kidney tissue filtration cells (glomeruli). Primary hyperlipidemia may be aided by omega-3 fatty acids (“good fats”) when used with a low-fat diet. Emerging areas for omega-3 fatty acids use in veterinary medicine include: inflammatory bowel disease (IBD), cancer, and to prevent brain aging changes.
Fatty acids should be used with caution in pancreatitis, platelet function abnormalities, in dogs with “sensitive stomachs” and diarrhea as fish oil can upset the gastrointestinal tract, they may cause interruptions in wound healing as well as weight gain. Veterinary therapeutic diets (VTD) may contain higher amounts of omega-3 fatty acids as a part of therapy so additional supplementation of exogenous fatty acids may throw off this balance of omega-3,6 fatty acids or result in high omega-3 levels. VTD’s are prescription diets used to control chronic diseases such as allergies, kidney failure, liver disease, inflammatory bowel disease, and osteoarthritis. Consultation with your veterinarian is essential as well as communicating with your doctor letting them know if the pet is already consuming fatty acids such as fish oil capsules. More is not necessarily better!
Supplementation with fish oil capsules if not consuming VTD’s for that purpose, should be done with veterinary products certified by NASC or consumerlab.com. Since supplements are not FDA regulated, NASC and consumerlab.com are 2 agencies that routinely hold supplement manufacturers to quality control. “FDA Approved laboratory” and “FDA-inspected facility” carry little to no meaning as the FDA does not approve laboratories and only a small percentage of dietary facilities are inspected by the FDA each year. You will find the NASC seal on containers of supplements if they are approved by NASC. Consumerlab.com is an online service that for a yearly subscription fee routinely evaluates supplements, drug interactions, laboratory tests (such as COVID tests), etc.
When selecting an omega-3 supplement, flaxseed oil and fish oil are both rich in omega-3 fatty acids. However, for flaxseed oil to have the same anti-inflammatory effects, the alpha-linolenic acid (ALA) must be converted to EPA and that conversion is only 10% in dogs. Cod liver oil should be avoided as it is too high in vitamins A and D and can cause toxicity of these vitamins. Home cooked diets can result in an essential fatty acid deficiency when fatty acids are provided from beef tallow, coconut oil, or olive oil, all of which do not have sufficient quantities of linoleic acid (LA) or ALA.
Fatty acid products should be used within the required expiration date, kept in a cool, dry storage area away from sunlight, and if via the diet, kept in the original bag. Fatty acids oxidize over time when not