Omega-3 Fatty Acids in Food
Omega-3 fatty acids (also abbreviated as n-3) are a very important group of compounds within the PUFA family (with more than one double bonds between carbon atoms). In a general sense, the term "omega" refers to the position of first double bond when counting from the far end of the molecule, that is in the "3," "6" and "9" positions of the carbon chain. The following table summarizes the main members of the PUFA group of nutrients with their sources.
Traditional Sources of Omega 3 and 6
* Omega 3
- DHA (docosahexaenoic acid) – fatty fish shellfish and algae [Editor’s note: as a food fortifier]
- EPA (eicosapentaenoic) – fatty fish
- ALA (alpha linolenic acid) – seeds, nuts, vegetable oils
* ARA (arachidonic) – egg yolk, meat and dairy
* LA (linoleic) – oil seeds (soy, flax, canola, cottonseed, etc.); nuts, borage oil; evening primrose
Benefits of n-3 Fatty Acids and the Ratio n-3:n-6
Clinical research has focused upon the nutritional benefits of the n-3 family for the cardiovascular and nervous systems. EPA and DHA are precursors of eicosanoids, which are effective in reducing inflammation and thrombosis. The n-6 PUFA family are the precursors to eicosanoids which, when produced in excess, may result in opposite effects -- that is inflammation and enhanced blood clotting. Thus there have been many recommendations made to balance dietary intakes of n-3 and n-6. Omega 6 fatty acid consumption is not undesirable in that they have their own nutritional benefits -- as essential fatty acids, they are critical for infant growth and development, and are staples ingredients. In "Western" style diets, an increased consumption of vegetable oils and food products rich in n-6 fatty acids has created an imbalance in the dietary ratio, which health organizations recommend should be in the range of 1:4 to 1:10 (n-3:n-6) but may be as high as 1:20 in the traditional Latin American diet, for example.
As noted, the essential fatty acids of both the n-3 and n-6 are necessary in fetal and infant brain development. Maternal diets that contain DHA in food or supplement form provide significant benefits to the proper development of the neuronal network of the newborn. This protective effect on nerve tissue is not unique to childhood, as recent research suggests reductions in the development of neurodegenerative diseases such Alzheimers and Parkinsons.
[Editors Note: In the U.S., the Institute of Medicine has set an Adequate Intake (AI) for ALA, based on the median daily intake of healthy Americans who are not likely to be deficient in this nutrient (Institute of Medicine, 2002). The AI is 1.6g ALA per day for men and 1.1g ALA per day for women. Up to 10% of the Adequate Intake for ALA can be provided by EPA and DHA.]
The American Heart Association has recommended two fatty fish servings per week for people who are healthy individuals without cardiovascular disease. The DHA plus EPA (combined) equivalency of such fish consumption is approximately 250-300mg/day. Several health authorities have suggested a daily intake of 650 mg of DHA plus EPA for normal healthy individuals. Current DHA plus EPA (combined) daily intakes range from 130-150mg/day in typical western style diets.]
Traditionally, the consumption of omega-3 in the marketplace has been in the form of soft capsules. Recently, the food industry has been experiencing a dynamic that allows the launching of new forms of this essential nutrient intake. The market is indeed growing and increasingly there are new opportunities to deliver to the consumer a healthy alternatives. Omega-3s are available in options that include not only capsules, but also yogurt, a loaf of bread or a slice of ham; the options appear limitless.
The basis of this article was first published in Industria Alimenticia, Prepared Foods’ sister publication
From the January 10, 2011, Prepared Foods E-dition