Omega-3 Fatty Acids

Alpha linolenic acid (Omega-6)

by Catherine M. Haug, December 2007; updated April 2019 (image, right, from Scientific Psychic (5))

As described in Fats & FattyAcids, The Omega number refers to the position of the last double bond in the fatty acid chain, as counted backwards from the last carbon (at the opposite end from the carboxylic acid (COOH) end of the chain).  Thus an Omega-3 fat has a double bond 3 bonds back from the end of the chain, as in the image, above right.

Common Omega-3 Fats

The most common Omega-3 Fats are: (7B)

  1. Linolenic Acid (LA)
  2. Alpha Linolenic Acid (ALA), 
  3. Eicosapentaenoic Acid (EPA),
  4. Docosahexanoic Acid (DHA).

Of these fats, only LA (and its other form ALA) is considered essential, but it is the longer chain EPA and DHA that are important for human metabolism.  

While EPA and DHA can be made from ALA, our bodies are not very efficient at this conversion (about 5 – 15%), so it is best to ensure you get all forms in your diet. 4 The most common food sources include deep water fish, krill oil, seal oil, organ meats, and egg yolks from properly raised chickens. 1

Benefits of Omega-3 Fats

They provide many benefits, including (5)

  1. Improve heart health;
  2. Reduce hypertension (high blood pressure);
  3. Improve autoimmune diseases;
  4. Improve depression;
  5. Aid cancer prevention and support;

Omega-3 fatty acids are precursors to specific eicosanoids. Eicosanoids are important for intercellular signaling. (7D)

Effect of insufficient Omega-3s

Both Omega-3 and Omega-6 fats are abundant in the cell membranes, where they are precursors of important chemical messengers. A deficiency in either, results in the necessity of using more saturated fats (or even the harmful trans fats if present in the diet) to construct cell membranes. While saturated fats are important in cell membranes, too many of them result in two significant consequences:

  • reduced ability to communicate with other cells (via chemical messengers); and
  • cell membranes are less elastic, a situation that makes the heart muscle stiffer and less able to return to a resting state (5)

Insufficiencies weaken certain immune functions; for example, Omega-3s are important in “helping cells resist infection with the herpes family of viruses and other similar organisms. Viruses have to penetrate the cell walls to reach the nucleus in order to reproduce. A healthy cell wall resists penetration while a weak cell wall is vulnerable.” (4)

Trans-fats (chemically altered fats) are known to cause problems for the heart, specifically hardening of the arteries (5).

Omega-3/Omega-6 balance

Dietary balance between these two types of fats is very important for our health. Most scientists agree their levels should be 1:1 ratio. One reason why this is so important is their affect on inflammation of tissues. Those made from most:

  • Most Omega-3 fats are anti-inflammatory;
  • Most Omega-6 fats are inflammatory; however, GLA (Gamma Linolenic Acid) is  considered a “good” omega-6 fat, because its effects are anti-inflammatory, like the omega-3 fats. See Omega-6 Fatty Acids, for more about this.

Because most Americans eat a diet high in omega-6 fats, we tend to have more inflammation in our body tissues. Increasing omega-3 fat consumption, especially those present in fish.

Essential Omega-3 fats

While most Omega-3 fats can be made by the body, the most important ones: EPA and DHA, are considered “essential,” because our bodies cannot make them. The best sources of these fats are wild-caught fish, krill and krill oil, fish oil, and cod liver oil.


The sources I take are Green Pastures Fermented Cod Liver Oil and Mercola’s Krill Oil. I also add freshly ground flax seeds to my morning smoothie. Note: all of these also provide Omega-6 fatty acids.

I also eat wild-caught salmon 1 -2 days a week, when in-season (late-spring to early fall), and wild-caught cod 1 – 2 days a week during the rest of the year. Other fish and/or seafood high in Omega-3 and Omega-6 fatty acids are crab, tuna, muscles and oysters. Wild-caught mackerel, sardines, anchovies, herring, catfish and trout are also high in Omega-3s.

The best supplemental sources of Omega-3 fats are:

  • Flax oil (ALA)
  • Fish oil (EPA, DHA)
  • Fish liver oil (EPA, DHA, vitamins A and D
  • Krill oil (EPA, DHA)

However, ALA, the omega-3 in flax and other plants, needs to be converted to EPA or DHA to be useful for humans. And while we do have enzymes that can make that conversion, it is complicated by feedback mechanisms, resulting in insufficient conversion. Therefore, it is important to include animal-based omega-3s in your diet (fish oil, fish liver oil, krill oil).

Enzyme supplements: It is important to remember that the body has difficulty digesting and absorbing any fats without help.  That is:

  • the enzyme lipase to remove the fatty acids from the glycerol backbone;
  • an emulsifier to mix the water-phobic fat with the watery chyme (what digesting food is called), so that lipase can do its work.

Most whole-food sources provide both of these; for example, raw egg yolks contain lecithin as an emulsifier and active lipase (cooking destroys the lipase).  But with supplementation, these must be added.  While the pancreas can excrete lipase for this purpose, it is more efficient if the lipase is provided by the food.  

Lecithin is an excellent dietary additive, because it not only emulsifies the fats during digestion, but also provides choline, which is essential for fat metabolism in the liver.

The best way to take supplemental fats is to mix the fat with a bit of lecithin and water or apple juice, and stir in some powdered fungal lipase.  Or mix the fat with a raw (or lightly coddled) egg yolk in a smoothie.


  1. The Skinny on Fats by Sally Fallon and Mary G, Enig, PhD
  7. Wikipedia:
    2. (8)

About Cat

See my 'About' page
This entry was posted in Diet, Health and tagged . Bookmark the permalink.