Fish Oil and Heart Support

Since 1980, when Kromann and Green reported low mortality from coronary heart disease in populations that consume large amounts of marine life that is rich in n-3 polyunsaturated fatty acids, much attention has been paid to studies investigating the effect of fish oil consumption on cardiac health.^5,6

Eskimo/Inuit populations (people inhabiting Greenland, the Arctic and Hudson Bay coasts of North America, the Labrador coast, Alaska, and the northeastern tip of Asia) have about one tenth the death rate from heart disease of that in many Western countries. This has led to interest in the beneficial effects of fish fatty acids. These fatty acids are abundant in the Inuit diet, the content of which is 20 times higher than in the European and American diet. Among the Inuit, joint and skin diseases are also uncommon. These three groups of diseases are ten times more common among Scandinavians than among Inuits.^5-8 (Figure 1)

Fig. 1. Incidence of various diseases among Scandinavians and Eskimos. From: Saldeen T. Fish Oil and Health with Focus on Natural Stable Fish Oil. Uppsala, Sweden: SwedeHealth Press; 1997:11. Based on information from: Kromann N, Green A. Epidemiological studies in the Upernavik district, Greenland. Incidence of some chronic diseases 1950-1974. Acta Med Scand. 1980;208:401-406.

How Does It Work?:
Fats and fatty acids
Saturated fatty acids are found primarily in land animal fats. Polyunsaturated fatty acids are found in plants and meat (omega-6) and in fatty fish (omega-3). Fatty acids are important components of fat. They are a part of all cell walls. The fatty acids are built up of carbon chains of different lengths. (Figure 2) Fatty acids are either saturated or unsaturated. Unsaturated fatty acids contain one or more double bonds. A double bond means that two adjacent carbon atoms have each lost one hydrogen atom and therefore bind to each other with a double bond instead of a single bond. The number and location of the double bonds in these fatty acids are of great importance for its function. The presence of many double bonds makes the fatty acids flexible, as well as sensitive to oxidation.^8,9

There are two types of polyunsaturated fatty acids, omega-3 fatty acids (fish fatty acids) and omega-6 fatty acids, both of which are essential for life. They must be supplied from food.^8,9
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are examples of omega-3 fatty acids. EPA is a precursor for the formation of prostaglandins that have beneficial effects on the liver, immune and cardiovascular systems.†^8,10 DHA is also important for the development and maintenance of neural structures such as the retina and brain.†^8,11 An important omega-6 fatty acid is arachidonic acid which is metabolized from linoleic acid. The major omega-6 polyunsaturated fatty acid consumed in the U.S. diet is linoleic acid.¹²

The fatty acid composition of the cells varies amongst different populations. People in Europe and the United States have high levels of omega-6 fatty acids such as arachidonic acid, and low levels of omega-3 fatty acids such as EPA in their cells. Research has shown that for European and American populations, the arachidonic acid to EPA ratio is approximately 50:1, and heart disease is common. Japanese people have a ratio of approximately 10:1, and demonstrate a lower incidence of heart disease. Greenland Eskimos have a very low incidence of heart disease and their ratio is approximately 1:1. These data indicate that the omega-6 to omega-3 ratio is extremely important in cardiovascular health.†^8,13

Saturated fatty acids have a straight structure, but omega-3 fatty acids are curved because of their double bonds. Saturated straight fatty acids are closely packed together in the cell wall, which becomes stiff, while curved fatty acids such as EPA and DHA take up more space so subsequently the cell walls are more flexible. This flexibility helps support healthy joint function as well as skin and blood vessel elasticity.†⁸

Saturated fatty acids are closely packed into a stiff cell wall while curved fatty acids such as EPA and DHA make the cell wall more flexible.

The beneficial effects of a natural stable fish oil on cardiovascular and heart health are due in part to the profile of fatty acids. Eskimo-3  has been shown to significantly increase blood levels of EPA and DHA. Benefits associated with these increases in omega-3 fatty acids include: support for healthy homocysteine levels, retention of healthy cholesterol levels that are already within normal limits, retention of healthy blood pressure, supporting healthy circulation, maintaining healthy lipoprotein levels, and protecting LDL from unfavorable oxidation.†^14,15

Homocysteine
Eskimo-3  supplementation has been shown to reduce homocysteine levels.†¹⁶ Changes in homocysteine levels in the blood can impact cardiovascular health.¹⁶

Blood Pressure
Eskimo-3  supplementation has been shown to support healthy blood pressure that is already within normal limits.† The primary mechanism is thought to be that of inhibiting thromboxane, which is a vasoconstrictor. Haglund, et al showed the effects of Eskimo-3  versus placebo in a clinical trial, which demonstrated superior support for maintaining healthy blood pressure that is already within normal limits.†^2,8

Healthy Circulation
Five separate studies on Eskimo-3  showed support for healthy circulation.†^2,3,17-19

Lipoprotein (a)
Clinical studies show that Eskimo-3  better supports healthy lipoprotein(a) [Lp(a)] levels than highly purified fish oil (HPFO).†³

Cardiovascular Health
In recent studies, intake of Eskimo-3  was found to support cardiovascular health.†^20,21

Eskimo-3  in Other Supportive Functions
Eskimo-3  is an antioxidant.†^22,23 Eskimo-3  provides support for musculoskeletal and joint health.†²⁴

Fish Oil Purity and Stability
Fish oils may naturally contain DHA and EPA, or they may be modified to artificially boost the concentration of DHA and EPA. Recent Norwegian studies have demonstrated that chemically modified fish oils are the least stable against lipid peroxidation (rancidity).^14,15 An unstable fish oil can cause an increase in malondialdehyde, a marker of free radical formation in the blood and tissues. Free radicals can contribute to less flexible blood vessels (atherosclerosis). Additionally, over-processing of fish oil supplements can result in a loss of key constituents and thus decrease their efficacy.^3,14,15

Eskimo-3  is purified by a proprietary process that preserves the beneficial key constituents of the whole oil.² Eskimo-3  has no detectable dioxin (a widely used toxic preservative), DDT (a toxic insecticide), PCB (polychlorinated biphenyls that are highly toxic to aquatic life) or heavy metals including mercury, lead, cadmium or copper.²⁵

Greenpeace Research Laboratories at Exeter University in the United Kingdom commissioned an independent laboratory to analyze twenty-two samples of fish oil. Twenty-one of the samples were found to contain detectable levels of organochlorine pesticides including DDT and PCBs. Reported DDT levels varied from 0 to 148 µg/L. Reported PCB levels varied from 0-1132 µg/L.²⁶ This demonstrates an enormous variability of contaminant level among fish oil products.

Eskimo-3  has been shown to be free of contaminants.²⁵ This level of purity for Eskimo-3  is attributed to a proprietary purification technique.^14,15

Eskimo-3  is stable against oxidation and protected by additional natural antioxidants, including mixed tocopherols (vitamin E).²⁷ This helps prevent rancidity and provides superior taste and efficacy.^14,15

References:
1. Written information from supplier. Cardinova International, Upsalla, Sweden. December 21, 2000.

2. Haglund 0, Wallin R, Luostarinen R, Saldeen T. Effects of a new fluid fish oil concentrate, Eskimo-3 , on triglycerides, cholesterol, fibrinogen and blood pressure. J Int Med. 1990; 227:347-353.

3. Haglund 0, Luostarinen R, Wallin R, SaIdeen T. Effects of fish oil on triglycerides, cholesterol, lipoprotein (a), atherogenic index and fibrinogen. Influence of degree of purification of the oil. Nutr Res. 1992;12:455-468.

4. Engström K, Luostarinen T, SaldeenT. Whole blood production of thromboxane, prostacyclin and leukotriene B4 after dietary fish oil supplementation in men. Effect of vitamin E. Prostaglandins Leukot Essent Fatty Acids.1996;54:419-425.

5. Kromann N, Green A. Epidemiological studies in the Upernavik district, Greenland. Incidence of some chronic diseases 1950-1974. Acta Med Scand. 1980;208:401-406.

6. Kromhout D. Bosschieter EB, de Lezenne Coulander C. The inverse relation between fish consumption and 20-year mortality from coronary heart disease. N Engl J Med. 1985;312: 1205-1209.

7. Bang HO, Dyerberg J, Sinclair HM. The composition of the Eskimo food in north western Greenland. Am J Clin Nutr. 1980;33:2657-2661.

8. Saldeen T. Effects of omega-3 fatty acids in cardiovascular and pulmonary disease. Tuberc Resp Dis. 1997;44:25-32.

9. Omega-3 fatty acid desaturase. On-line Medical Dictionary. Available at: http://www. Graylab.ac.uk/cgibin/omd?query=Omega03+fatty+acids&action=Search+OMD. accessed January 26, 2001.

10. Connor WE, DeFrancesco CA, Connor SL. N-3 fatty acids from fish oil. Effects on plasma lipoproteins and hypertriglyceridemic patients. Ann NY Acad Sci. 1993;683:16-34.

11. Moriguchi T, Greiner RS, Salem N Jr. Behavioral deficits associated with dietary induction of decreased brain docosahexaenoic acid concentration. J Neurochem. 2000;6:2563-2573.

12. Ziegler EE, Filer LJ Jr. eds. Present Knowledge in Nutrition. 7th ed. Washington D.C.: ILSI Press; 1996:434.

13. Saldeen T, MD, Ph.D. Cardinova International, Scientific Advisor. Written communication (electronic mail). January 25, 2001.

14. Appleton J, Ackerson A. Health Benefits of a Natural Stable fish Oil. Adv Stand. 1998; 1:1-2.

15. Saldeen T, Wallin R, Marklinder I. Effects of a Small Dose of Stable Fish Oil Substituted for Margarine in Bread on Plasma Phospholipid Fatty Acids and Serum Triglycerides. Nutr Res. 1998;18:1483-1492.

16. Haglund 0, Hamfelt A, Hambraeus L, Saldeen T. Effects of fish oil supplemented with prydoxine and folic acid on homocysteine, atherogenic index, fibrinogen and plasminogen activator- I in man. Nutr Res. 1993;13:1351-1365.

17. Haglund 0, Wallin R, Wreting S, Hultberg B, Saldeen T. Effects of fish oil alone and combined with long chain (n-6) fatty acids on some coronary risk factors in man. Acta Universitatis Upsaliensis. 1993;428:1-22.

18. Haglund 0, Mehta JL, Saldeen T. Effects of fish oil on some parameters of fibrinolysis and lipoprotein(a) in healthy subjects. Am J Cardiol. 1994;74:189-192.

19. Haglund O, Saldeen T, Mehta J. Effect of Fish Oil on some Parameters of Fibrinolysis. In: Glas-Greenwalt P, ed. Fibrinolysis in Disease. Boca Raton, Fl: CRC Press, Inc; 1995:102-109. Review.

20. Saldeen T, Luostarinen R, Haglund 0, Wallin R. N-3 fatty acids and ischemic heart disease. 17th Nordic Lipid Symposium, Imatra, Finland, June 1993.

21. Saldeen T, Luostarinen R, Mehta JL. N-3 fatty acids and sudden cardiac death. In: N-3 Fatty Acids: Prevention and Treatment in Vascular Disease. London, England: Kristensen SD, ed. Springer Verlag; 1995:125-139.

22. Yang BC, Saldeen TGP, Bryant JL, Nichols WW, Mehta JL. Long-term dietary fish oil supplementation protects against ischemia-reperfusion-induced myocardial dysfunction in isolated rat hearts. Am Heart J. 1993;1287-1292.

23. Luostarinen R, Saldeen T. Dietary fish oil decreases superoxide generation by human netrophils: relation to cyclooxygenase pathway and lysosomal enzyme release. Prostaglandins Leukot Essent Fatty Acids. 1996;55:167-172.

24. Saldeen T, Engstrom K, Jokela R, Wallin R. Importance of In Vitro Stability for In Vivo Effects of Fish Oils. In: Natural Antioxidants and Anticarcinogens in Nutrition, Health and Disease. Cambridge, England: The Royal Society of Chemistry Special Publication 240; 1999:326-330.

25. Written information from supplier. Cardinova International, Upsalla, Sweden. December 21, 2000.

26. Jacobs MN, Johnston PA. Organochlorine pesticides and PCB residues in pharmaceutical and industrial grade fish oil. Greenpeace Research Laboratories, technical note 05/95, May 4, 1995.

27. VanGoethem B. Enzymatic Therapy Quality Assurance Department. Providing Information from Cardinova. Stability Studies of Cardinova's Fish Oil Products. March 23, 2001.