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General Information About Omega-3 Essential Fatty Acids

Health Canada, the World Health Organization and the American Heart Association all recommend an increased daily intake of omega-3. That is because omega-3 is essential from infancy to old age for normal growth and development, but cannot be produced by the human body.

Omega-3 essential fatty acids are a group of polyunsaturated acids that include three essential parts: 1) eicosapentaenoic acid (EPA); 2) docosahexaenoic acid (DHA); & 3) docosapentaenoic acid (DPA). Omega-3 is deemed essential because it is necessary from infancy to old age, but cannot be produced by the human body.

All three omega-3 essential fatty acids circulate in the blood stream under normal conditions, but are lost through age. It is therefore important to supplement with an omega-3 product that contains all three omega-3 essential fatty acids (EPA, DHA and DPA).

Eicosapentaenoic Acid (EPA)

Numerous studies from various countries over extended time periods have documented that increased consumption of EPA appears to be associated with lower primary and secondary heart attack rates and death from cardiovascular disease, as well as reduced all-cause mortality (Kris-Etherton, et al., 2002) (He, et al., 2004).

A very strong inverse relationship between higher levels of EPA and reduced risk of sudden cardiac death has been reported in men without prior incidence of cardiovascular disease (Albert, et al., 2002). Furthermore, population studies also reveal a lower risk of coronary heart disease in those with higher levels of marine-derived omega-3 fatty acids in their bloodstream (Simon, et al., 1995). A 2003 study published in the American Journal of Clinical Nutrition reported a 70% lower risk of fatal ischemic heart disease in those with higher levels of EPA and DHA in their blood stream, as compared to those with low levels (Lemaitre, et al., 2003).

Docosahexaenoic Acid (DHA)

DHA is recognized as a physiologically-essential nutrient in the brain and retina for neuronal functioning and visual acuity, respectively (Youdin, 2000) (Holub, 2001). Large amounts of DHA are deposited during the prenatal and postnatal period into the lipid-rich neuronal tissues of the brain and retina during growth development. Furthermore, a continual delivery of DHA to the brain is needed throughout life to balance the continual turnover in cell membranes. Other omega-3 fatty acids such as alpha-linolenic acid (ALA) are found in only trace amounts in neural tissue regardless of the amounts consumed in the diet (Burdge, et al., 2002) (Burdge and Wooten, 2002) (Emken, et al., 1994).

A number of population studies have positively correlated the presence of DHA in breast milk with the accretion of DHA in the brain and enhanced intellectual development (Youdin, 2000) (Muskiet, et al., 2004). DHA intake and status during maternal nutrition and pregnancy has also been related to improve birth weight and head circumference of babies (Cunnane, et al., 2000). Infants consuming DHA exhibit a higher rate of brain and whole body DHA accumulation. Higher levels of DHA in the body have been positively correlated with better childhood intelligence and also improved cognitive function in old age (Whalley, et al., 2004).

Docosapentaenoic Acid (DPA)

Population studies have indicated that various Inuit groups including those living in Greenland and in northern Quebec (Nunavik) have a lower prevalence of cardiovascular disease-related mortality (Dyerberg and Bang, 1979) (Dewailly, et al., 2001). The Inuit consume considerable amounts of marine mammal oils (seal oil) containing DPA in addition to EPA and DHA in their traditional diet. All omega-3 fatty acids from marine mammal sources are considered to be readily incorporated into body tissues (Ackman, 1988). Interventional studies with seal oil supplementation (containing natural DPA in addition to EPA and DHA) have indicated a significant elevation in the circulating levels of all three omega-3 fatty acids (Conquer, et al., 1999). A 2011 study found considerable benefits offered by higher levels of DPA (Mozaffarian, et al., 2011).

The Kupio Ischemic Heart Disease Risk Factor Study showed that men with higher levels of DPA plus DHA in their blood serum lipid had 44% reduced risk of acute coronary events (Rissanen, et al., 2000). Higher intakes of EPA, DHA and DPA as reflected in adipose tissue contents have been inversely associated with the risk of myocardial infarction (Pedersen, et al., 2000). Controlled human trial with seal oil supplementation have indicated, in some studies, a significant reduction in circulating plasma triglyceride levels (Bonefeld-Jorgensen, et al., 2001); elevated triglycerides are recognized as a significant risk factor for myocardial infarctions. Furthermore, seal oil supplementation in humans has been found to favourably increase EPA and DHA levels in serum phospholipids as associated with a lower risk of fatal ischemic events (Conquer, et al., 1999) (Lemaitre, et al., 2003). In one study, DPA was found to be up to 10 times as effective as EPA in stimulating the migration of endothelial cells (Kanayasu-Toyoda, et al., 1996).

References

Albert, et al. Blood levels of long-chain n-3 fatty acids and the risk of sudden death. NEJM, 346: 1113-1118, 2002.

Bonefeld-Jorgensen EC, et al. Modulation of atherosclerotic risk factors by seal oil: a preliminary assessment. Int. J. Circumpolar Health, 60: 25-33, 2001.  

Burdge GC, Jones AE, Wootton SA. Eicosapentaenoic and docosapentaenoic acids are the principal products of alpha-linolenic acid metabolism in young men. BJN, 88: 355-363, 2002.

Burdge, et al. Conversion of alpha-linolenic acid to eicosapentaenoic, docosapentaenoic and docosahexaenoic acids in young women. BJN, 88: 411-420, 2002.

Conquer JA, et al. Effect of supplementation with dietary seal oil on selected cardiovascular risk factors and hemostatic variables in healthy male subjects. Thromb. Res., 96: 239-250, 1999.

Cunnane SC. Breast-fed infants achieve a higher rate of brain and whole body docosahexaenoate accumulation than formula-fed infants not consuming dietary docosahexaenoate. Lipids, 35:105-11, 2000.

Dewailly, et al. n-3 Fatty acids and cardiovascular disease risk factors among the Inuit of Nunavik. Am. J. Clin. Nutr., 74:464-473, 2001.

Dyerberg J, and Bang HO, Haemostatic function and platelet polyunsaturated fatty acids in Eskimos. Lancet, 2: 433-435, 1979.

Emken EA, Adolf RO, Gulley RM. Dietary linoleic acid influences desaturation and acylation of deuterium-labelled linoleic acids in young adult males. Biochim. Biophys. Acta.  1213: 277-288, 1994.

He, et al. Accumulated evidence on fish consumption and coronary heart disease mortality: a meta-analysis of cohort studies. Circulation, 190: 2705-2211, 2004.

Holub BJ. Docosahexaenoic Acid in Human Health. Chapter in: Shahidi F and Finley JW (eds), Omega-3 Fatty Acids Chemistry, Nutrition, and Health Effects. (Washington DC, American Chemical Society, 2001) Chapter 5, p. 54-65.

Kanayasu-Toyoda T, et al. Docosapentaenoic acid (22:5, n-3), an elongation metabolite of eicosapentaenoic acid (20:5, n-3), is a potent stimulator of endothelial cell migration on pretreatment in vitro. Prost. Leukot. Essent. Fatty Acids, 54: 319-325, 1996.

Kris-Etherton PM, et al. Fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease. Circulation, 106: 2747-2757, 2002.

Lemaitre, et al. n-3 Polyunsaturated fatty acids, fatal ischemic heart disease, and nonfatal myocardial infarction in older adults: The Cardiovascular Health Study. Am. J. Clin. Nutr., 77: 319-325, 2003.

Mozaffarian D, et al. Circulating long-chain omega-3 fatty acids and incidence of congestive heart failure in older adults: the cardiovascular health study. Annals of Internal Medicine, 155: 160-170, 2011.

Muskiet FAJ, et al. Is docosahexaenoic acid (DHA) essential? Lessons from DHA status regulations, our ancient diet, epidemiology and randomized controlled trials. J. Nutr., 134: 183-186, 2004.

Pedersen JI, et al. Adipose tissue fatty acids and risk of myocardial infarction – a case-control study. Eur. J. Clin. Nutr., 54: 618-625, 2000.

Rissanen T, et al. Fish oil-derived fatty acids, docosahexaenoic acid and docosapentaenoic acid, and the risk of acute coronary events. Circulation, 102: 2677-2679, 2000.

Simon JA, et al. Serum fatty acids and the risk of coronary heart disease. Am. J. Epidemiol., 142: 469-476, 1995.

Whalley LJ, et al. Cognitive aging, childhood intelligence, and the use of food supplements: possible involvement of n-3 fatty acids. Am. J. Clin. Nutr., 80:1650-7, 2004.

Youdin KA. Essential fatty acids and the brain: possible health implications. Int. J. Neurosci., 18: 383-399, 2000.