Omega-3 Fatty Acids: Their Role in Inflammation

What are essential fatty acids?

There are three essential fatty acids. They are called essential to human health because the body cannot make them. They are the Omega-3s, the Omega-6s and the Omega-7s. Another fatty acid is called Omega-9. It is not essential since the body can make it. Omega-7s are relatively new, but have been found to be useful in maintaining normal blood sugar levels. Omega-3 fatty acids can be found in salmon, tuna and halibut as well as in other marine life such as algae and krill. The Omega-3s can also be found in certain plants and nuts/nut oils. The American Heart Association (AHA) recommends eating fish (particularly fatty fish such as mackerel, lake trout, herring, sardines albacore tuna and salmon) at least two times per week. Pregnant women and mothers, nursing mothers, young children and women who might become pregnant should not eat several types of fish (swordfish, shark, and king mackerel) due to the possibility of contaminants like mercury. They should also limit the consumption of other fish like albacore tuna, salmon and herring also because of possible contamination, especially in farm-raised fish. They can take Omega-3 fatty acids in quality dietary supplements that are mercury-free (sometimes labeled molecularly distilled).

Major Types of Omega-3s

Once eaten, the body converts ALA to EPA and DHA. This isn’t as efficient as we age. EPA and DHA are the two types of Omega-3 fatty acids more readily used by the body. Extensive research indicates that Omega-3 fatty acids reduce inflammation and help prevent risk factors associated with chronic diseases such as heart disease, cancer and arthritis. These essential fatty acids are highly concentrated in the brain and appear to be particularly important for cognitive (brain memory and performance) and behavioral function. Infants who do not get enough Omega-3 fatty acids during pregnancy are at risk for developing vision and nerve problems. Symptoms of Omega-3 fatty acid deficiency include extreme tiredness (fatigue), poor memory, dry skin, heart problems, mood swings, depression and poor circulation.

Types of Essential Fatty Acids

There are two types of EFAs: Omega-3 and Omega-6 fatty acids. They are called essential because we cannot make them. They must be supplied in the foods we eat. Both Omega-3 and Omega-6 fatty acids are stored in the cell membranes of tissues and have two primary functions. Firstly, they are structural components of cell membranes where they ensure fluidity, stability and act as gate-keepers in the cell (they allow certain things to pass into the cell and others to not). Secondly, both Omega-3 and Omega-6 fatty acids are converted into a number of important, active molecules called prostaglandins.

What Are Prostaglandins?

There are 3 types of prostaglandins: PG1, PG2 and PG3. Some of the prostaglandins have beneficial effects and some not. PG1 has many beneficial effects. They include:

  1. Reduces inflammation
  2. Inhibits blood clotting
  3. Maintains various regulatory states of the body
  4. Strong anti-inflammatory properties help the body recover from injury by reducing pain, swelling and redness.

PG2 has the opposite effect of PG1. It has been found to:

  1. Strongly increase inflammation
  2. Constrict blood vessels
  3. Encourage blood clotting

PG3 has a mixture of of functions in the body. These include:

  1. Decreasing the rate at which PG2 is formed
  2. Anti-inflammatory properties since they reduce the effect of PG2

To understand how these PGs work, let’s look at an example. In people with heart disease, inhibition of PG2 is desirable due to the inflammation in the progression of disease. Studies have found that high Omega-3 intake decreases the production of PG2 (promotes inflammation). To understand how Omega-3 fatty acids inhibit inflammation, I need to briefly go over the pathways by which the Omega-3 and Omega-6 fatty acids are processed in the body. Although most Omega-3 and Omega-6 fatty acids are generally referred to as “essential” fatty acids, we only need two of them in our metabolism. Linoleic Acid (LA) of the Omega-6 family and Alpha Linolenic Acid (ALA) of the Omega-3 family are the truly “essential” fatty acids. Once we have LA or ALA, our bodies have the enzymes that can convert these fatty acids into all the other different types of Omega-3 and Omega-6 fatty acids. Both Omega-3 and Omega-6 fatty acids use the same enzymes for conversion and they both compete for the same amount of enzymes to produce their final products. Studies have shown that the enzymes prefer the Omega-3 pathway, so diets high in Omega-3s use these enzymes preferentially. In a diet low in Omega-3 fatty acids, the enzymatic pathway converts the fatty acids into the inflammatory PG2. The more Omega-3 fatty acids present in our bodies, the fewer enzymes are available for converting Omega-6 fatty acids into the inflammatory prostaglandins.

PG2 has the opposite effect of PG1. It has been found to:

  1. Strongly increase inflammation
  2. Constrict blood vessels
  3. Encourage blood clotting

PG3 has a mixture of of functions in the body. These include:

  1. Decreasing the rate at which PG2 is formed
  2. Anti-inflammatory properties since they reduce the effect of PG2

Standard American Diet or Western Diet

A balance of Omega-3 and Omega-6 fatty acids is crucial for good health. The typical Western diet has evolved to be high in Omega-6 and low in Omega-3 fatty acids (about 25-30 Omega-6 to 1 Omega-3). Omega-6 fatty acids are not necessarily bad, but a skewed ratio in favor of too much Omega-6 can be detrimental to one’s health. In addition, there appears to be a relationship with vitamin E and the essential fatty acids. Inadequate intake of vitamin E results in a decreased absorption of Omega-3 fatty acids.

Sources of the essential fatty acids

  1. LA of the Omega-6 family is found in most plant oils (corn, safflower, canola, sunflower), nuts seeds and soybeans. Remember, if these aren’t organic, they may be GMO (unlabeled).
  2. ALA of the Omega-3 family is found only in oil from cold marine animals (cod liver oil, sardines, mackerel, anchovies) and flax oil. Omega-3 fatty acids from fish are a direct source of EPA and DHA, while flax seed oil yields ALA which must then be converted into DHA and EPA (human conversion is slow).
  3. Ideally, you want the ratio of Omega-6 to Omega-3 fatty acids to be 1:1.