Modulation of atherosclerotic risk factors by seal oil: a preliminary assessment.

Bonefeld-Jorgensen EC, Moller SM, Hansen JC.
Department of Environmental and Occupational Medicine, University of Aarhus, DK-8000, Aarhus, Denmark. ebj@mil.au.dk

We examined whether dietary supplementation with seal oil influenced the risk factors of atherosclerosis in healthy volunteers. Two intervention studies were carried out as preliminary steps in a larger project which aim at elucidating the disease preventive potential of seal oil. In study I ten healthy volunteers added 10 capsules of seal oil to their normal Western diet for six weeks. Blood tests were analysed for total-, HDL-, and LDL-cholesterol and plasma triglyceride, and the ratio of n-6/n-3 fatty acid was determined in plasma and erythrocyte membranes. In study II we examined the effect in five healthy volunteers who had only 5 capsules of seal oil daily for six weeks. As an additional test in study II, the effect on the proinflammatory TNF-alpha cytokine in lymphocytes was determined. A slightly decreased, however, not significant effect was observed for each of the cholesterol's after seal oil supplementation. In both studies plasma triglyceride, and the n-6/n-3 fatty acid ratio of plasma and erythrocytes were significantly reduced upon seal oil intake. During the intervention period of study II a distinct reduced level of TNF-alpha was observed in isolated lymphocytes. The examinations suggest that supplementation of seal oil, 10 capsules or 5 capsules/day, may have beneficial effects on factors thought to be associated with cardiovascular and thrombotic diseases.

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Chapter IV
Seal Oil
The Studies of Seal Oil
Effects of Dietary Marine Oils and Olive Oil on Fatty Acid Composition, Platelet Membrane Fluidity, Platelet Responses, and Serum Lipids in Healthy Humans.

Vognild E, Elvevoll EO, Brox J, Olsen RL, Barstad H, Aursand M, Osterud B.

The influence of various dietary marine oils and olive oil on fatty acid composition of serum and platelets and effects on platelets and serum lipids were investigated as part of an extensive study of the effects of these oils on parameters associated with cardiovascular/thrombotic diseases. Oils such as cod liver oil (CLO); whale blubber oil (refined or unrefined); mixtures of seal blubber oil and CLO, or olive oil/CLO were cosumed. In conclusion, intake of various marine oils causes changes in platelet membranes that are favorably antithrombotic. The combination of CLO and olive oil may produce better effects than these oils given separately. The changes in platelet function are directly associated with alterations of fatty acid composition in platelet membranes. 
Effect of Marine Oils Supplementation on Coagulation and Cellular Activation in whole Blood.

Osterud B, Elvevoll E, Barstad H, Brox J, Halvorsen H, Lia K, Olsen JO, Olsen RL, Sissener C, Rekdal O, et al.

A study was performed to explore the effects of supplemental intake of various marine oils to be part of the Eskimo diet. Oils such as: oil from blubber of seal, cod liver, seal/cod liver, blubber of Minke whale. Supplementation of regular diet with a combination of seal oil and CLO and especially with whale oil seems to have beneficial effects on several products thought to be associated with cardiovascular and thrombiotic diseases.
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.

Toshie Kanayasu – Toyoda, Ikou Morita, Sel-itsu Murota
Department of Psychological Chemistry Graduate School
Tokyo Medical and Dental University
Yushima, Bunkyo-ku, Tokyo 113 Japan

Many factors such as hypercholesterolaemia, hypertension and oxidation modifies low-density lipoprotein induce endothelial cells (EC) injury. Which results in various pathological disorders including atherosclerosis and thrombosis. EC migration and proliferation are important processes in the control of wound healing responses of blood vessels. EC migration and proliferation also place a central role in the healing following traumatic injury due to balloon catherization, graft placement or organ transplantation. We discovered by lipid analysis that a large amount of docosapentaenoic acid (DPA 22:5 n-3) the elongated product of EPA existed in EC Phospholipids.  Other studies have also reported an increase in the DPA content of Phospholipids bovine (cows) and human umbilical veins. EC followed EPA pretreatment. In general  EPA and docosapentaenoic acid (DHA 22:6, n-3) and major components of fish oil, both substances are often used to investigate the effects of fish oil.

We have demonstrated that the simulative effect of EPA of EC Migration may be due to DPA. Moreover the potency of DPA stimulation of EC migration is ten – fold greater than that of EPA.
Involvement of liptogenous pathways in docosapentaenoic acid introduced inhabitants of platelet aggression

Yamashina – ku, Kuoto 607 – 8414, Japan
Department of Pathological Biochemistry Kyoto Pharmaceuticals University Missasagi

The effects of docosapentaenoic acid (DPA) on platelet aggression and Arachidonic acid Metabolism

The results of this study suggest that DPA possesses potent activity for interfering with the cyclooxygenase pathways thus inhibiting platelet aggression most effectively. Epidemiological studies have revealed that low incidence myocardial infraction in the Greenland Inuit’s who live mainly on seals (1-2)

Seal oil contains a significant amount of docosapentaenoic acid (22-5n-3 DPA) Eicosapentarnoic acid (20:5n-3 EPA) and Docosahexaenoic acid (22-6n-3, DHA) compared with fish oil recently the biological and pharmacological effects of DPA and the antiatherosclerotic and antithrombotic effects of Seal Oil supplements were reported.
Effect of supplementation with dietary seal oil on selected cardiovascular risk factors and haemostatic variables in healthy male subjects.

Conquer JA, Cheryk LA, Chan E, Gentry PA, Holub BJ.
Department of Human Biology, University of Guelph, Ontario, Canada.

The average daily consumption of seal oil by the Inuit people is approximately 8-9 g, yet there is very little information on the effect of seal oil consumption on cardiovascular disease risk factors. In this study, 19 healthy, normocholesterolemic subjects consumed 20 g of encapsulated seal oil containing eicosapentaenoic acid 
(EPA; 20:5n-3), docosahexaenoic acid (DHA; 22:6n-3), and docosapentaenoic acid (DPA; 22:5n-3) or 20 g of vegetable oil (control) per day for 42 days. Levels of selected cardiovascular and thrombotic risk factors as well as fatty acid profiles of serum phospholipid and nonesterified fatty acid (NEFA) were determined. EPA levels in serum phospholipid and NEFA increased by 4.3- and 2.7-fold, respectively, in the seal oil supplemented group. DHA levels rose 1.5- and 2.1-fold, respectively, and DPA levels rose 0.5- and 0.7-fold, respectively. Arachidonic acid (AA) levels dropped by 26% in both serum phospholipid and serum NEFA. There was a significant decrease in the ratio of n-6 to n-3 fatty acids in serum phospholipid from 7.2 to 2.1 and a significant increase in the ratio of EPA/AA in NEFA. Ingestion of seal oil raised the coagulant inhibitor, protein C, values by 7% and decreased plasma fibrinogen by 18%. No alterations in other hemostatic variables, including plasma activity of Factors VII, VIII, IX, and X and antithrombin, or in the concentrations of von Willebrand Factor, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, glucose, Apo A-1, or lipoprotein(a) were observed in either group. Other risk factors for cardiovascular disease, including hematocrit, white blood cell count, plasma viscosity, systolic and diastolic blood pressures, heart rate, and platelet aggregation after stimulation with ADP or collagen did not change. Our results indicate that seal oil supplementation in healthy, normocholesterolemic subjects decreased the n-6/n-3 ratio and increased EPA, DHA, and DPA and the ratio of EPA/AA and DHA/AA in the serum phospholipid and NEFA, while exhibiting a modest beneficial effect on fibrinogen and protein C levels.

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Lower Prevalence of Impaired Glucose and Diabetes associated with Daily Seal Oil or Salmon Consumption Among Alaskan Natives.

A study to examine the association of salmon and seal oil consumption with impaired Glucose tolerance (IGT) and
non – insulin – dependant diabetes mellitons (NIDDM) among Alaskan natives was tabulated in “Diabetes Care” December 1994 the study concluded the consumption of SEAL OIL and Salmon high in Omega 3 fatty acids appeared to lower the risk of glucose intolerance and is a potentially modifiable risk factor for NIDDM in Alaskan natives.

A look at the eating habits and blood tests of six hundred and sixty six people over the age of forty revealed that those who ate salmon everyday had a fifty percent chance of having any glucose intolerance (which includes Diabetes and Pre-Diabetes) than people who ate that fish less often. The risk dipped even lower (down to an 80% reduction in risk) for daily consumption of SEAL OIL.
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