A lipid (sometimes used synonymously with the word fat) is the term used to encompass all water-insoluble biological molecules.  Examples of lipids are fatty acids and all of their derivatives (mono-, poly-, trans-, saturated, and omega fatty acids) as well as, metabolites such as cholesterol and its variety of particle sizes (LDL, HDL, ect.).  Lipids are a vital component of our cells and needed for proper metabolism. Lipids provide four main functions:   1) They serve as structural components in our cell membranes 2) They provide energy reserves for the body at 9 kcal/g  3) Both lipids and lipid derivatives serve as vitamins and hormones  4) Fat loving bile acids aid in lipid solubilization for proper absorption and digestion.

This entry will focus primarily on types of fatty acids and their use in our body.  Fatty acids come from the break down of triglycerides and phospholipids in our diet.  Fatty acids are grouped and classified by the number and location of double bonds they carry.  If they contain no double bonds are called saturated fats, and all of the carbons along the molecule are attached to hydrogen.  Being saturated makes the molecule rigid and causes it to have greater energy storage or more calorie dense.  If the molecule contains one or more double bonds it is unsaturated.   A fatty acid is a monounsaturated fatty acid (MUFA) if it contains one double bond, and polyunsaturated (PUFA) if it contains more than one double bond.  The greater the degree of unsaturation in a fatty acid (i.e., the more double bonds it contains) the more vulnerable it is to rancidity.  Antioxidants can help prevent PUFA’s from becoming rancid and producing oxygenated free radicals (exactly what we don’t want).  Saturated fats are often used in processed foods because they are less vulnerable to rancidity and are in general, more solid at room temperature than unsaturated.  By replacing saturated fats with unsaturated fats in your diet you can lower both total and LDL-cholesterol in your blood.

Another type of unsaturated fatty acid is called Trans unsaturated fat or simply trans-fats.  These molecules contain hydrogen atoms on opposite sides of the molecule and this allows the molecule to assume a linear conformation.  These types of fatty acids are particularly risky because the structure allows them to lay down and pack efficiently within the blood vessel leading to increased plaque formation.  These fats, like saturated fats, tend to solidify at room temperature making them a desired product to be used in processed foods.  Trans fats are found in shortening and hydrogenated oils.

Now on to the omegas…  Humans require dietary intake of omega fatty acids because the body can not make them.  Because of this they are called essential or EFA’s, for essential fatty acids.  Omega 6 and omega 3 are the essentials that we must incorporate into our diets.  They are named based on where the double bond is placed in the fatty acid molecule.

Omega 3 fatty acids or α-linolenic acid (ALA) is considered to be an anti-inflammatory EFA and is required for healthy membranes and proper nerve function.

The omega 3 family promotes health and helps to prevent degenerative diseases.  However, most North Americans consume insufficient omega 3 foods and tend to eat excessive amounts of saturated fats from animal (non-fish) sources.   Omega 3’s as shown above can be obtained by a diet rich in leafy greens, cold water fish, flaxseed oil, and grass fed animal products.

DHA: primary structural component of the human brain and retina

EPA: able to lower inflammation, also can help in cases of depression and ADHD

Omega 6 or Linoleic acid is another essential fatty acid that must be obtained from our diet.  Omega 6 is found in many different types of oils with the richest sources being sunflower and safflower followed by pumpkin seed oil, soybean, walnut, wheat germ, and sesame oil listed in descending order.  Omega 6 is also found in supplemented form such as in primrose oil, borage, and black currant seed oil.

Omega 6 fatty acids are essential for health, but excessive amounts may promote cancer as they are known to be pro-inflammatory. Below is a chart listing both omega’s and their products.

It’s really all about balance between omega 6 and omega 3.  The average Western diet has a ratio of around 16:1  omega 6 to 3, when we should be aiming for a ratio of around 2:1.

“Excessive amounts of omega-6 polyunsaturated fatty acids (PUFA) and a very high omega-6/omega-3 ratio, as is found in today’s Western diets, promote the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases, whereas increased levels of omega-3 PUFA (a low omega-6/omega-3 ratio) exert suppressive effects.” (1)

So, grab your fish oil and your flaxseed grinder and balance your omegas!  Make note that flaxseed is useless unless it is ground and once you grind it make sure to store it in the refrigerator so it does not become rancid.  Also, buy quality fish oil not fish oil from Costco or Walgreens.  You want to know what is in those capsules you are taking each morning with your breakfast.  Many supplements are not regulated and do not have quality assurance standards to meet so the fish oil could contain mercury or other dangerous contaminates.  Get your fish oil from a trusted source.  Ask your doctor which one they recommend.  Liquid is better than capsules because you get more bang for your buck. You would have to take up to 4 capsules to equal one teaspoon of liquid in some cases.  Taking fish oil with food helps you digest it more efficiently and prevents the fishy burps some people find they have when taking it alone.

References:

1. Simopoulos, AP. The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomedical Pharmacotherapy. 2002 Oct;56(8):365-79.