Omega 3 Supplements: What You Should Know


author:  Kelly Gill, MS, RD, CSSD, LD


I get questions about supplements all the time.  I thought I’d address the question of fatty acid supplements because it is a very confusing topic.

The first thing you need to know about supplementation, in general, is that it is never as good as getting nutrients from food.  So, anytime I talk about supplements, keep that in mind.

Omega 3 fatty acids are considered essential nutrients because our bodies cannot make them – we have to eat them.  There are a lot of health benefits tied to these fatty acids.  We see considerable benefits with two particular types of omega 3 fatty acids called eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

DHA and EPA are predominantly found in fatty fish.   Fatty fish with DHA and EPA include anchovies, artic char, bluefish, herring, lake trout, mackerel,  salmon, sardines, and tuna.  The American Heart Association recommends eating fatty fish twice a week.  The dietary guidelines recommend Americans eat 8 oz fatty fish per week.


Intake of fatty fish has been linked with the following benefits:

  • Reduced inflammation (which helps prevent onset of chronic and autoimmune diseases)
  • Reduced risk of autoimmune disease, including type I diabetes, psoriasis, and Rheumatoid arthritis
  • Curb stiffness and joint pain in rheumatoid arthritis
  • Lowered risk of certain cancers, including breast, skin, oral, and prostate cancer.
  • Lowered risk for heart disease, including stroke and heart failure
  • Decreased risk of dying from a heart related event
  • Decreased triglycerides in people with elevated triglycerides
  • Increased High Density Lipoprotein (HDL) cholesterol, which is the good cholesterol
  • Decreased rate of plaque build up in the arteries
  • Decreased risk of arrhythmia’s (abnormal heart beat)
  • Slightly decreased blood pressure
  • Reduced blood clotting
  • Relieves dry, itchy skin and brittle hair and nails
  • Decreased risk of age-related macular degeneration
  • Linked to brain health – may protect it from age-related deterioration
  • May be linked to neuro development in babies when taken during pregnancy
  • Decreased risk of dementia and Alzheimer’s disease
  • Possible link to lower levels of depression and may boost the affects of antidepressants
  • May reduce inflammation associated with brain injury
  • May minimize soreness after intense workouts
  • May prevent asthma in children plus possible link to aiding in the management of asthma


Read this article for tips on buying fatty fish, and this article lists the amount of fatty acids in various foods.


Omega 3 fatty acids are also available from plant sources in the form of Alpha-linolenic acid (ALA).  Sources of ALA include canola oil, flaxseed, hemp oil, rapeseed oil, pumpkin seeds, soybean oil, and walnuts.  Approximately 10% of ALA converts to DHA and EPA, so it doesn’t have the same impact on health as DHA and EPA.


The typical American diet does not get the recommended 8 oz of fatty fish per week.  A lot of people are turning to Omega 3 supplements.  Unfortunately, we don’t quite see the same benefits with supplementation that we see with eating oily fish, but we definitely see benefits and that is hopeful!


Benefits seen with Fish Oil Supplementation from multiple publications:

  • Very strong link to significantly reduced triglycerides in people with higher baseline triglycerides
  • Very strong link to minor reduction in blood pressure in people with elevated blood pressure (no reduction for those with normal pressure)
  • Very strong link to minor increase in High Density Lipoprotein (HDL) cholesterol (good cholesterol)
  • Very strong link to notable decrease in symptoms of systemic lupus erythematosus
  • Very strong link to minor decrease in symptoms of depression in severe bipolar disorder (no reduction seen with lower severity depression and no change in manic symptoms); more studies are needed
  • Very strong link to minor reduction in symptoms of Attention Deficit Hyperactive Disorder (ADHD) in children
  • Strong link to notable decreased depression in people with major depressive disorder (not seen with minor depressive disorder)
  • Moderate link to minor decrease in some inflammatory markers
  • Link to minor decrease in Low Density Lipoprotein (LDL) cholesterol (bad cholesterol) in people with normal LDL levels for those on LDL lowering medication (seems to augment the medication), but there is a possibility that it may actually increase LDL cholesterol in people with elevated TG or LDL cholesterol levels, which is not a benefit.
  • Link to minor decrease of cognitive decline in elderly (more with DHA than EPA)


Other findings with only 1-2 studies (which means more studies are needed before we can draw conclusions) include:

  • Decreased anxiety
  • Deceased Cortisol levels
  • Increased exercise induced oxidation and general oxidation
  • Enhanced memory
  • Enhanced processing accuracy in healthy adults
  • Decreased reaction time in healthy adults who don’t consume enough dietary fatty fish
  • Increased in overall well-being


Not all omega 3 supplements are equal.  Here are 3 things you need to keep in mind when purchasing supplements.


  1. First, make sure they contain only DHA and EPA, any other fatty acid in addition to those two are fillers and not worth the money.  For example, if it has DPA, that is an intermediate fatty acid, not an omega 3 fatty acid.  Look at the label and compare one supplement with another.
  2. Second, the presence of contaminates should be a consideration.  Fish naturally can contain toxic chemicals like metals, including mercury and lead, as well as other contaminants.  You can request a certificate of analysis (COA) that is conducted by an independent laboratory.  If the company cannot furnish a COA, I wouldn’t trust the product.  In addition, look for supplements that undergo third party testing.
  3. Third, there are 4 forms of DHA and EPA supplementation from fish oil and each has different absorption rates, which are usually reflected in the price:
    • Triglycerides (natural fish oil) – considered the standard
    • Re-esterified Triglycerides (natural fish oil that is concentrated and purified) – enhanced absorption by 25% of the standard (TG)
    • Ethyl Esthers (synthetic fish oil) – diminished absorption by 33% of the standard (TG)
    • Phospholipids (Krill Oil) – enhanced absorption by 33% of the standard (TG), but not heavily researched in terms of benefits



Remember, DHA and EPA are readily available from fish oil.  So to supplement DHA and EPA, you should be taking a fish oil supplement.  With that said, it is not vegan.  There is one vegan source of DHA and EPA from microalgae called phytoplankton.  Supplement is called “algae oil”.  Any other plant-based source for omega 3 fatty acids will be in the form of ALA and will not contain the same benefits as DHA & EPA.



The recommended daily amount of omega 3 fatty acids is 1000-1200 mg/day of EPA and DHA (combined); if you eat 8 oz fish per week, you don’t need to supplement.  Since most of us don’t eat enough fish, supplementation has proven to be beneficial and worth the investment.  Don’t take it for granted that all supplements are the same.  Do your research when purchasing supplements, keeping in mind the three things to look for.

Also, keep in mind, supplements are not well regulated.  Refer to this blog for more information to help you navigate the supplement industry.



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