Inflammation: It’s All About The Fat
Veterinarian Reviewed on September 9, 2017 by Dr. Janice Huntingford, DVM
Posted in Cat
Fatty acids are a vital source of energy because dietary fat has a higher caloric density than carbohydrates or proteins. Many of the fats widely viewed as energy sources come from meats and oils. Those referred to as essential fatty acids have biological functions and are incorporated into membranes of every cell within the body.
Fats can be saturated (very firm) or monounsaturated (thick oils) or polyunsaturated (liquid). All essential fatty acids are polyunsaturated. These fats have a more fluid consistency and can form a variety of bioactive molecules that will be discussed below:
Omega 6 Fatty Acids
Linoleic Acid – This is an 18 carbon polyunsaturated fatty acid that is crucial for your pet’s diet. Found in many plant, seed, or grain oils, linoleic acid is heavily involved in the formation of a molecule called ceramide, which helps hold the skin cells together. Low fat diets can make your dog or cat’s skin flaky, giving the coat a dull appearance. Certain oils high in linoleic acid can offset this effect.
The oils with the highest linoleic acid content are safflower, sunflower, corn and soybean oils. Linoleic acid is known as an omega 6 fatty acid, which have a bad reputation for being pro-inflammatory. This is because the body converts linoleic acid to a slightly longer fatty acid found only in meats and certain fungi called arachidonic acid. During an inflammatory reaction, arachidonic acid makes prostaglandin E2, which incites inflammatory cells to make more inflammatory molecules called cytokines. This is why omega 6 fatty acids have traditionally been discarded from diets. Only dogs, however, can efficiently convert linoleic acid to arachidonic acid unlike cats, which therefore have an arachidonic acid requirement.
Omega 3 Fatty Acids
Omega 3 fatty acids are also polyunsaturated fatty acids, meaning they have a fluid-like consistency and are only found in certain plant sources in high concentrations (canola and flax) or marine sources (fish, krill, crustaceans, algae). Those found in plants like flax and canola are known as alpha linolenic acids and are similar to the omega 6 fatty acid linoleic acid in that they are both 18 carbon fatty acids. They have no real biological value – unless the body elongates them to another fatty acid called eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA). Unfortunately, both dogs and cats have a hard time converting omega 3’s. Therefore, flax seed and canola oils have limited value regarding bioactivity and it is much more effective to provide these longer chain fatty acids in the diet from the marine sources above.
From a biological perspective, including EPA or DHA in the diet can slowly push arachidonic acid from the cell membranes and replace them with these two omega three fatty acids. When this happens, immune cells activate and release the EPA and DHA from the membranes, converting them into things that are inert, like prostaglandin E3. This prostaglandin will not act on local immune cells to further cytokine release, which helps dampen the inflammatory reaction.
When looking at pet food, we might like to see these longer chain omega three fatty acids but it is very hard for us to determine if the amount added by the companies is enough to help our companions. The problem is there is a lot of calculating to do and not many companies label the amount of omega three fatty acid on the bag. When they do, it will be the total omega three as a percentage. In this case, it may say something like “0.4% omega three fatty acid” – but we don’t know if this is from alpha linolenic acid or from our friends EPA and DHA. Looking at the label can provide some information in the ingredient list.
Typical ingredients will be flax seed oil, flax seed meal, fish oil, canola oil, canola meal, or algae (labeling for this is tricky – it may be called “fat product”). Some fish meals have most of the fat extracted from the product while others do not, making the label even harder to interpret. The best thing to do is call the company and ask them what the percentage of EPA and DHA is in the product you are interested in.
How To Calculate Accurate EPA And DHA Content
Let’s say you call the company and they tell you the concentration is 0.2% EPA and DHA. The next step is to do some math based on the amount that is currently perceived as beneficial for health and mild inflammation, which is around 20-30 mg per pound of body weight. For example; let’s take a 60 lb Labrador with allergic skin problems that needs this basic anti-inflammatory dose. Calculations would suggest that the dog needs 1200-1800 mg of EPA/DHA. The food that she is eating has 0.2% EPA/DHA. We now need to know how much food the dog consumes each day. A typical cup of extruded dry diet has about 70-120 grams per cup. Again, you need to examine information from the bag to calculate the relative grams per cup of food. 3 cups per day comes out to around 279 grams of food, 0.2% of which is EPA and DHA. This equates to close to 0.6 grams or 600 mg of EPA/DHA. Most foods will actually have even less than this and therefore must be supplemented with marine oils.
If supplementation is necessary, we must figure out how much omega three is in the typical fish oil capsule. Most capsules contain 250 mg per 1000 mg. This is because most whitefish is only 25 % EPA and DHA, so only ¼ of the total fish oil is the bioactive portion. The amounts of EPA/DHA in fish range from about 12-30%, therefore you need to read labels carefully because in some cases, you can get double or triple strength purified EPA and DHA products. Remember, the average Labrador needing 1200-1800 mg will need many tablets rather than just 2 -1000 mg soft gels. In fact, the ideal amount would actually be around 5-6 of the 1000 mg of typical soft gel fish oil tablets every day.
This supplementation regimen is designed for alleviation of modest inflammation and can be used to combat numerous conditions including itchy skin (atopy), kidney disease, liver disease, and inflammatory bowel disorders. Diseases like osteoarthritis and cancer, however, may require additional ingredients, which will be discussed in future articles. This dose applies to cats with the same diseases as well.
It’s actually easier to treat cats because most need ¼ to ½ teaspoon of fish oil each day, as size does not vary as much as dogs. Most fish oils contain 1200 mg of EPA + EHA per teaspoon. Still, some cats may be extra sensitive to fish oil, possibly developing blood clotting problems. This is why cat owners should be cautious about doubling or tripling doses, like we can with dogs. These are a few things to keep in mind when supplementing long chain omega three fatty acids for inflammation and the dose provided on the manufacturer’s bottle is basically just a starting point.
Box 1: Gram conversion from label information:
Bag will say 3750 kcals/kg
This equals 3.75 kcals/gram
Bag will say 350 kcals/cup
Divide 350/3.75 = 93.3 grams/cup
Box 2: Determining the EPA/DHA content of the food:
EPA/DHA content is 0.2%
93.3 grams x 0.002 = 0.186 grams
This is 186 mg per cup
Dog eats 3 cups per day = 558 mg per day
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Janice Huntingford, DVM, has been in veterinary practice for over 30 years and has founded two veterinary clinics since receiving her Doctor of Veterinary Medicine at the Ontario Veterinary College, University of Guelph. She has studied extensively in both conventional and holistic modalities. Ask Dr. Jan