A Rundown of Omega-3 Fatty Acids

What are they?

Omega-3 fatty acids are a group of polyunsaturated fatty acids. The hallmark of an unsaturated fatty acid is that one or more carbons in the compound have less than the maximum amount of chemical bonds. This is important because unsaturated fatty acids are less flexible and prone to creating plaques. Unsaturated fatty acids are thought to increase LDL ("good cholesterol"), and decrease the incidence of coronary artery disease, heart attacks, and sudden cardiac death. There is some evidence they may ease symptoms of rheumatoid arthritis, and studies are underway examining the neuroprotective effects. Early data suggests it lowers the risk of dementia, Alzheimer's disease, and other conditions1. Humans don't make essential fatty acids like omega-3s, so it's important to reach adequate intake in one's diet. There are several different possible sources.

Where do they come from?

There are three key types of omega-3 fatty acids. Alpha-linolenic acid (ALA) is mainly found in vegetable oils. Flaxseed oil is particularly rich in ALA, but more common sources are soybean and canola oil. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are usually found in seafood: salmon, tuna, and shellfish. A small amount of ALA can be converted into DHA and EPA in the body.



Fish or fish oil supplements are one of the most common sources of omega-3s in a diet. It is effective both biologically and cost-wise. The supplements themselves are safe to consume and don't cause side effects. However, they may be unsuitable for people with fish or shellfish allergies, vegetarians and vegans, and those looking to minimize mercury content or environmental impact.

There is an ongoing concern about mercury contamination, particularly for small children and pregnant women. It has been shown that larger and more predatory fish have higher levels of mercury. Tuna (particularly albacore and ahi) and other large fish like marlin, swordfish, and shark are best eaten in moderation s or avoided by at-risk groups. Smart choices for maximizing omega-3 consumption without ingesting excessive methymercury include salmon and shrimp2. Mercury contamination is typically very low in supplements. They tend to be produced from cold-water oily fish like salmon, herring, anchovies, and sardines.


Krill oil is gaining more attention as a source of omega-3s. It is Generally Recognized as Safe (GRAS) by the FDA and is very well tolerated. It is an interesting alternative to fish oil for several reasons.

Scientifically speaking, krill oil may pack more of a punch. One study found that a lower dose of krill oil was just as metabolically effective as almost 33% more fish oil.3. It is possible that krill oil is more easily metabolized, has greater bioavailability, and increases the omega-3 index better than fish oil4.

Environmentally, krill may be a better option as concerns mount over the sustainability of fishing and the ecological harm caused by overfishing. Krill has one of the greatest biomasses of any organism, estimated at hundreds of millions of tons. However, further studies must be done on how disrupting that enormous biomass could negatively impact a global ecological balance. Furthermore, this population could be endangered by global warming and rising sea levels.

Because krill oil supplements tend to be more expensive than fish oil supplements, a good compromise may be to take a supplement that combines the two.

Plant Matter


Algae is an excellent vegetarian/vegan alternative source. Studies have shown it to have comparable efficacy to fish sources in terms of protecting from cardiovascular disease and oxidative stress5. Algae-derived oil is also just as effective as fish oil at enriching meats or other foods with omega-3s6.

From a sustainability standpoint, algal supplements may be one of the best options. Algae is cultivated, rather than harvested from a non-renewable natural source. There are types of algae that don't require any type of organic carbon source, lessening opportunity for contamination7. Furthermore, cultivating these types of algae could serve multiple purposes. The omega-3 fatty acids can be refined, and the remaining biomass can be used for biodiesel or animal feed. This algae does not require fresh water to cultivate, making this a source of omega-3s with minimal environmental impact.

Transgenic Oil Crops

New research is examining ways to bioengineer plants capable of producing omega-3 fatty acids8. If successful, it would be a sustainable alternative to marine life sources and would allow the production of enriched food.

Our Recommendation

Omega-3 fatty acids are an important nutrient that can only be obtained through diet or supplementation. They promote cardiovascular and joint health, along with cognitive well-being. As most people find it difficult to achieve recommended levels through diet alone, daily supplementation is a great idea. Krill oil, or a supplement combining krill and fish oil, is an excellent source. Algae-derived supplements are an appropriate substitution for vegetarians or vegans.

  1. Fotuhi, M., Mohassel, P., & Yaffe, K. (2009). Fish consumption, long-chain omega-3 fatty acids and risk of cognitive decline or Alzheimer disease: a complex association. Nature Reviews Neurology 5, 140-152.

  2. Mahaffey, K., Clickner, R.P., & Jeffries, R.A. (2008). Methylmercury and omega-3 fatty acids: Co-occurrence of dietary sources with emphasis on fish and shellfish. doi:10.1016/j.envres.2007.09.011

  3. Ulven, S.M., Kirkhus, B., Lamglait, A., Basu, S., Elind, E., Haider, T., Berge, K., Vik, H., & Pedersen, J. (2010). Metabolic Effects of Krill Oil are Essentially Similar to Those of Fish Oil but at Lower Dose of EPA and DHA, in Healthy Volunteers. DOI: 10.1007/s11745-010-3490-4

  4. Ramprasath, V.R., Eyal, I., Zchut, S., & Jones, P.H. (2013). Enhanced increase of omega-3 index in healthy individuals with response to 4-week n-3 fatty acid supplementation from krill oil versus fish oil. DOI: 10.1186/1476-511X-12-178

  5. Doughman, S.D., Krupanidhi, S., & Sanjeevi, C.B. Omega-3 Fatty Acids for Nutrition and Medicine: Considering Microalgae Oil as a Vegetarian Source of EPA and DHA. (2007). Current Diabetes Reviews, Vol. 3, Number 3. pp. 198-203(6).

  6. Rymer, C., Gibbs, R.A., & Givens, D.I. (2009). Comparison of algal and fish sources on the oxidative stability of poultry meat and its enrichment with omega-3 polyunsaturated fatty acids. Poultry Science 89 (1): pp. 150-159.

  7. Adarme-Vega, T.C, Lim, D., Timmins, M., Vernen, F., Li, Y., & Schenk, P.M. (2012). Microalgal biofactories: a promising approach towards sustainable omega-3 fatty acid production. Microbial Cell Factories 11:96. DOI: 10.1186/1475-2859-11-96.

  8. Venegas-Caleróna, M., Sayanovaa, O., & Napie, J.N. (2010). An alternative to fish oils: Metabolic engineering of oil-seed crops to produce omega-3 long chain polyunsaturated fatty acids. Progress in Lipid Research. Vol. 49, Issue 2, Pages 108–119.

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