Essential Fatty Acids

Lipids in the human body exist in three major forms which are sterols, phospholipids, and triglycerides.  The types of fats that this topic will cover are those that are found primarily in triglycerides.  A triglyceride is a group of three fatty acid molecules that are bound to a glycerol molecule.  A fatty acid is a hydrocarbon chain (fat) with a carboxyl group (acid) at one end.  There are some important facts about fat and some of these are:

A saturated fat is one where the carbon atoms are saturated with hydrogen.

A monounsaturated fat has one missing pair of hydrogen bonds while a polyunsaturated fat has 2 or more missing pairs.

Omega 3 and omega 6 fatty acids are polyunsaturated fats with the first missing hydrogen pairs on the third and the sixth carbon atoms respectively (from the hydrocarbon end).

The shapes and polarities of these molecules give them vital roles in our cellular physiology.

Our bodies have the capability to desaturate fats by removing hydrogen pairs from many positions but not from the third or the sixth positions.

Because our bodies need fats with these particular hydrogen pairs removed but cannot remove them, we need to ingest some fats with these hydrogen pairs removed.

This makes omega 3 and omega 6 fatty acids essential in our diet.

These fats, although beneficial, are somewhat unstable and are easily destroyed.

Excessive heat and processing can twist the fat molecules to place the missing hydrogen pairs across from each other and into the trans (Latin for across) configuration thus creating trans fatty acids.

The altered shapes of these trans fatty acids adversely affect their function in our cellular physiology with potentially severe health consequences.

These harmful molecules are abundantly formed during the hydrogenation process where hydrogen is forced into polyunsaturated fats under intense heat and pressure.

The best way to satisfy our requirements for essential fats is to eat relatively small amounts from sources that are high in essential fats.  These sources also make good transport media for fat soluble micronutrients.  However, once the body's maximum needs are satisfied, any additional amount becomes empty calories.  Also, the fact that we need some fats is not a good reason to eat large quantities of poor quality fat sources.  This would result in fattening ourselves with empty calories while still remaining deficient in the essential fats (which is happening across the USA).

It is important to note that most dietary fats are stored in the fat cells first before the body uses them.  This is because any fats that contain more than 12 carbons in each chain, is absorbed into the lymphatic system where they eventually empty into the thoracic duct after which the heart pumps them out to the fat cells.  Most of the fats that we eat, including the essential fats, contain at least 18 carbons in each chain.

For someone on a fat loss program, fats should be ingested primarily to provide essential fats as well as to provide a transport medium for fat soluble micronutrients.  If the body needs fats for any other function (such as energy), then it can tap into its own fat stores.  This is the entire objective of a fat loss program.  Excellent sources of essential fatty acids include flax seeds, pumpkin seeds, and walnuts.  They also include oily fish such as salmon, tuna, and trout provided that they are not burned or otherwise overcooked.  If you take supplements for fat soluble micronutrients, then they are best taken with these types of foods.  We need to avoid trans fatty acid sources such as highly processed cooking oils and hydrogenated oils such as margarine.  We also need to stay away from anything that is deep fried.