Cell membranes are composed of lipids (fats). As raw materials for the body to construct healthy cell membranes and for proper cell function, the body needs both saturated fats for structure and unsaturated for flexibility.
Saturated fat molecules have no double bonds along the carbon chain–all carbon atoms are saturated with hydrogens, lending stability. In contrast, unsaturated fats are more reactive. Along their carbon chain, they have one or more double bonds–places where carbon atoms are not paired with a full complement of hydrogens. At these double-bond “hot spots” they are more vulnerable to oxidative stress and free-radical damage. While the more double bonds, the more fragile, the more double bonds, the more effective these oils are to provide the body with materials necessary for cellular communication and neurological function.
This table, adapted from Elson Haas, illustrates food sources of a variety of unsaturated oils. Note the 5 and 6 double bonds of fish oils, a reason fish are thought to be “brain food.”
Source: Adapted from Elson Haas, Staying Healthy With Nutrition
Monounsaturated Omega-9 Oleic acid 18 carbons 1 Olive oil
Polyunsaturated Omega-6s Linoleic acid 18 carbons 2 Safflower, sunflower, Sesame, and Gragpesee Oils
Gamma-linolenic acid 18 carbons 3 Borage, Evening Primrose Oils
Arachidonic acid 20 carbons 4 Beef fat, Egg Yolk
Polyunsaturated Omega-3s Alpha-linolenic acid 18 carbons 3 Flax, Pumpkin, Hemp, Seeds and Walnuts
Eicosapentaenoic acid (EPA) 20 carbons 5 Fish oil
Docosahexaenoic acid (DHA) 22 carbons 6 Fish oil
Source: Adapted, Elson Haas