What are omega 3 fatty acids? Omega-3 fatty acids are a family of unsaturated fatty acids. Nutritionally important fatty acids include α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), all of which are polyunsaturated. The human body cannot synthesize fatty acids from new, but it can form “long chain” fatty acids like EPA or DHA from the “short chain” ALA. These conversions occur competitively with omega 6 fatty acids, which are essential closely related chemical analogues that are derived from linoleic acid.
Omega 3 and 6 Products
Currently there are many omega 3 fatty acid supplements on the market which claim to contain health promoting ‘omega 3’, but contain only α-linolenic acid (ALA), not EPA or DHA. These products contain mainly higher plant oils and must be converted by the body to create DHA and therefore considered less efficient.
New versions of “ethyl esterized” omega-3 fatty acids, such as E-EPA and combinations of E-EPA and E-DHA, have drawn attention as highly purified and more effective products than the traditional ones. In the United States, these are often sold as prescription medications, such as Lovaza. In the European Union, they are available as dietary supplements as omega 3 fatty acid capsules.
Conversion efficiency of ALA to EPA and DHA
It has been reported that conversion of ALA to EPA and further to DHA in humans is limited, but varies with individuals. Men (at 5%)[4have lower ALA conversion efficiency than women (greater than 5%)  , probably due to the lower rate of utilization of dietary ALA for beta-oxidation.
This suggests that biological engineering of ALA conversion efficiency is possible.
History of fatty acids
The ‘essential’ fatty acids were given their name when researchers found that they were essential to normal growth in young children and animals.
Although omega-3 fatty acids have been known as essential to normal growth and health since the 1930s, awareness of their health benefits has dramatically increased in the past few years. The health benefits of omega 3 fatty acids — DHA and EPA omega-3 — are the best known.
These benefits were discovered in the 1970s by researchers studying the Greenland Inuit Tribe. The Greenland Inuit people consumed large amounts of
fat from seafood, but displayed virtually no cardiovascular disease. The high level of omega-3 fatty acids consumed by the Inuit reduced triglycerides, heart rate, blood pressure, and atherosclerosis.
- Holman RT (February 1998). “The slow discovery of the importance of omega 3 essential fatty acids in human health”. J. Nutr. 128 (2 Suppl): 427S–433S. PMID9478042.
- Burdge GC, Calder PC (September 2005). “Conversion of alpha-linolenic acid to longer-chain polyunsaturated fatty acids in human adults.”. Reprod. Nutr. Dev. 45 (5): 581–597. doi:10.1051/rnd:2005047. PMID 16188209.
- “Conversion Efficiency of ALA to DHA in Humans”. Retrieved 21 October 2007.
- Gerster H (1998). “Can adults adequately convert alpha-linolenic acid (18:3n-3) to eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3)?”. Int. J. Vitam. Nutr. Res. 68 (3): 159–173. PMID 9637947.
- Brenna JT (March 2002). “Efficiency of conversion of alpha-linolenic acid to long chain n-3 fatty acids in man.”. Curr. Opin. Clin. Nutr. Metab. Care 5 (2): 127–132. doi:10.1097/00075197-200203000-00002. PMID 11844977.