We all come from families, fatty acids do too! These fatty acid families and associations are helpful when learning the differences.
Fatty Acid Families of Oils carbon-chain
Oils and fats fall into families characterized by the degree of saturation of the oils in the group. The following is a brief description of each oil family.
The “omega” designation is determined by the number of carbon atoms attached from the free end, the omega end, of the fatty acid to the first double bond from the omega end, the free fatty end. The first double bond occurs at the third carbon atom in an omega-3 fatty acid. In an omega-9 monounsaturated oil, it occurs at the ninth carbon atom. Only unsaturated fatty acids have omega numbers.
Super-Unsaturated, Omega-3 Family
Super-Unsaturated, Omega-3 Family: the most unsaturated, with three double bonds. It includes the essential alpha-Linolenic acid (18:3), LNA, of which flaxseed oil is the highest vegetable source. This group also contains stearidonic acid (18:4), SDA, found in black currant seed oil, as well as eicosapentaenoic (20:5) acid, EPA, and docosahexaenoic acid (22:6), DHA, which are found in cold-water fish and marine animals.
Super-Unsaturated, Omega-5 Family
Super-Unsaturated, Omega-5 Family: includes punicic acid (18:3), from pomegranate, a highly nutritious, long-chain fatty acid, with 18 carbons, and super-unsaturated with three conjugated double bonds. Monounsaturated myristoleic acid from nutmeg and eleostearic acid found in cherry kernels are also of this family.
Polyunsaturated, Omega-6 Family
Polyunsaturated, Omega-6 Family: has two double bonds and includes the essential linoleic acid, LA, found in safflower, sunflower, hemp, soybean, walnut, and sesame oils. Also included in this group is gamma-Linolenic acid, GLA, found in borage, black currant seed, and evening primrose oil. Arachidonic acid, AA, found in meats and other animal products, and dihomo-gamma-linolenic acid (DGLA), found in human breast milk, is also included here.
Monounsaturated, Omega-7 Famil
Monounsaturated, Omega-7 Family: represented by palmitoleic acid, POA, which is found in tropical oils such as coconut and palm kernel. It has one double bond in a 16-carbon fatty acid chain (16:1). Vaccenic acid (18:1) named from the Latin for cow, vacca, is found in dairy sources, including milk, butter, and human breast milk. A version, cis-vaccenic acid, is also found in Sea Buckthorn oil.
Monounsaturated, Omega-8 Family
Monounsaturated, Omega-8 Family: one representative of this family is the rare margaroleic acid (17:1) found in fish and animal fats primarily and occasionally in plant oils..
Monounsaturated, Omega-9 Family
Monounsaturated, Omega-9 Family: Mono means one double bond in the 18-carbon fatty acid chain. This major family is represented by oleic acid, OA, (18:1), a fatty acid found in large quantities in many oils: olive, avocado, almond, macadamia nut, pecan, and peanut oil are a few. Erucic acid is a long-chain fatty acid with 22-carbon chain, but only one double bond (22:1).
Saturated Family: includes stearic acid, SA, found in red meat, butter, cocoa butter, and shea butter; palmitic acid, PA, found in tropical fats; butyric acid, BA, found in butter; and arachidic acid, found in peanuts.