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

Chemical Composition of Seal Oil

Seal oil is naturally available as a triglyceride, which is ideal for superior absorption. Most fish oils are ethyl ester concentrates that have been chemically altered to yield higher levels of EPA and DHA. This process makes fish oil concentrates less effective for absorption than seal oil. Faster absorption ensures that more omega-3 essential fatty acids are absorbed and used by the body.

The distribution of fatty acids in seal oil differs from that of fish oil. Chemical analysis of the structure of seal oil shows that EPA, DHA and DPA are mainly distributed in the first and third position, compared to fish which is mainly in the second position.

Seals, like humans, are mammals. Therefore, seal oil triglycerides have the same first and third distribution of fatty acids as human triglycerides. The fact that seal oil triglycerides have the same structure as the triglycerides of humans ensures that seal oil is readily digested and the omega-3 fatty acids routed by the same pathways to where they are most needed (Ackman, 1988). The position of fatty acids in seal oil is considered superior to fish oil because it allows for faster digestion, and ultimately absorption, of EPA, DHA and DPA (Shahidi, et al., 1996) (Christensen M, et al., 1996).

Importance of DPA

Unlike fish oil, seal oil contains docosapentaenoic acid (DPA). DPA is found to circulate in the blood stream under normal conditions. However, we lose DPA as we age and can only replace it through our diet.

Numerous studies have highlighted the importance of DPA:

- DPA was found to be 10 times more effective than EPA in repairing damaged vessel walls (Kanayasu-Toyoda, et al., 1996)

- All omega-3 fatty acids from marine mammal sources are considered to be readily incorporated into body tissues (Ackman, 1988)

- Men with higher levels of DPA plus DHA in their blood serum lipid had 44% reduced risk of acute coronary events (Rissanen, et al., 200)

- DPA has a potent inhibitory effect on angiogenesis (Tsuji, et al., 2003)

- DPA increases total serum omega-3 (Conquer, et al., 1999)

- DPA found to reduce prostacyclin production in endothelial cells (Benistant, et al., 1996)

- DPA has anti-inflammatory activity and enhances the effects of DHA (Neuroth, et al., 2010)

- DPA is recognized as an essential nutrient by the Ministry of Health in Australia and New Zealand (Link)

Safety of Seal Oil

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. The Inuit consume considerable amounts of marine mammal oils (seal oil) containing DPA in addition to EPA and DHA in their traditional diet. 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. A 2011 study found considerable benefits offered by higher levels of DPA (Mozaffarian, et al., 2011).

 

Triglyceride Compared to Ethyl Ester

When examining omega-3 essential fatty acids, bioavailability refers to the capability of an omega-3 source to absorb in the body. The chemical form of an omega-3 source will influence its bioavailability. The two most common forms of marine omega-3 sources are natural triglycerides and ethyl esters, but there are also re-esterfied triglycerides (Nuronner, et al., 2010).

 

All marine sources of omega-3 are available as natural triglycerides. This is the ideal structure of omega-3 for superior absorption (Dyerberg, et al., 2010) because the structure of omega-3 has not been chemically altered. DPA GOLD Omega-3 seal oil capsules and liquids are available exclusively as natural triglycerides.

Most fish oils are not natural triglycerides, but ethyl esters (concentrates). The ethyl ester process concentrates EPA and DHA levels in the fish oil to yield higher amounts of both essential fatty acids. This process also reduces the absorption capabilities of fish oil, thus making ethyl ester fish oils less effective for absorption than natural triglyceride seal oils (Dyerberg, et al., 2010) (Mann, et al., 2010).

Re-esterfied triglycerides are usually fish oil concentrates that have been altered back to the triglyceride form. While this chemical form is superior to the ethyl ester from, it is not as effective for absorption when compared to the natural triglyceride chemical form.

References

Ackman RG, Some possible effects on lipid biochemistry of differences in the distribution on glycerol of long-chain n-3 fatty acids in the fats of marine fish and marine mammals. Atherosclerosis, 70: 171-173, 1988.

Benistant C, et al. Docosapentaenoic acid (22:5, n-3) metabolism and effect on prostacyclin production in endothelial cells. Prost. Leukot. Essent. Fatty Acids, 55: 287-293, 1996.

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

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

Christensen M, et al., Effects of dietary triacylglycerol structure on triacylglycerols of resultant chylomicrons from fish oil-and seal oil-fed rats. Lipids 31(3): 341-344, 1996

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, et al., Bioavailability of marine n-3 fatty acid formulations. Prostaglandins, Leukotrienes and Essential Fatty Acids 83(3): 137-141, 2010.

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

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. Lueko. Essent. Fatty Acids, 54: 319-325, 1996.

Mann NJ, et al. Effects of seal oil and tuna-fish oil on platelet parameters and plasma lipid levels in healthy subjects. Lipids, 45(8): 669-681, 2010.

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.

Neubronner J, et al. Enhanced increase of omega-3 index in response to long-term n-3 fatty acid supplementation from triacylglycerides versus ethyl esters. Eur. J. Clin. Nutr. 65(2): 247-254, 2010.

Neuroth JM, et al. Docosahexaenoic acid (DHA) and docosapentaenoic acid (DPAn-6) algaloils reduce inflammatory mediators in human perippheral mononuclear cells in vitro and paw edema in vivo. Lipids, 45(5): 375-382, 2010.

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.

Shahidi F, et al. Seal blubber oil: a novel source of ω3 fatty acids. Journal of Food Lipids, 3(4): 293-306, 1996.

Tsuji M, et al. Docosapentaenoic acid (22:5, n-3) suppressed tube-forming activity in endothelial cells induced by vascular endothelial growth factor. Prost. Leukot. Essent. Fatty Acids. 68: 337-342, 2003.