Positive Health Online

Most of us suffer from a deficiency of fish fatty acids (omega-3 fatty acids)

Our intake of different fats has changed markedly during the last century. We eat much more saturated fats and vegetable oils containing omega-6 fatty acids today, whereas our intake of fish fatty acids (omega-3) has decreased by 80% during the last 80 years. In the old days it was not uncommon for fish to be eaten seven days a week and some people working on Swedish farms would ask for a note in their employment contracts stating that salmon would not be served more than five days a week. We eat much less fish today, so most of us now suffer from a deficiency of omega-3 fatty acids. This may be of great physiological importance and may also relate to an increased incidence of cardiovascular disease and other disease states. To keep up with the needs for fish fatty acids, we should eat 100 gram daily of fatty fish such as mackerel, herring or salmon.

Ocean deep water fish stay supple in the very cold water due to their high content of omega-3 fatty acids

If the tissues of ocean deep water fish did not contain such a large amount of omega-3 fatty acids, they would become stiff and would not survive in the very cold water. Omega-3 fatty acids also keep cells supple and flexible in Man, helping to maintain joint suppleness and skin and blood vessel elasticity. Such supple, flexible cells are said to be signs of youth. Omega-3 fatty acids are important constituents of the cell walls, and determine physiological properties of cell walls such as fluidity (plasticity). This depends primarily on the structure of the fatty acids.

Saturated fatty acids have a straight structure, whereas omega-3 fatty acids like EPA and DHA are markedly curved. Saturated, straight fatty acids are closely packed together in the cell wall, which becomes stiff, while curved fatty acids such as EPA and DHA cannot be packed so closely, take more space and make the cell walls more plastic and less stiff.

Eskimos have a high intake of omega-3 fatty acids and a low incidence of heart, joint and skin problems

The low death rate from heart disease among Eskimos, about one tenth of that in many Western countries, has led to interest in the beneficial effects of fish fatty acids, such as EPA and DHA. These fatty acids are abundant in the Eskimo diet, where their content is 20 times higher than in the European and the American diet. Among the Eskimos not only heart disease but also joint and skin diseases are uncommon.

Fish oil concentrates can be natural or chemically modified, and stable or unstable

Fatty fish should be an ideal source of omega-3 fatty acids. However, most fish today are contaminated with environmental poisons. Another problem is that fatty fish become rancid immediately after death. That is the reason why Chinese people bring home their fish from the shop in a living state. A third problem is that the fatty acids can be destroyed during the preparation of the fish, e.g. grilling or frying. These are some reasons why fish oils have been developed as substitution for fish. Several fish oil preparations containing omega-3 fatty acids are now available either as natural fish oil concentrates or as chemically modified products. Natural fish oil has a maximal concentration of omega-3 fatty acids of 38%. If a fish oil has a higher concentration of omega-3 fatty acids it is chemically modified. Chemically modified products of three different types are available, namely those containing: 1) triglycerides where the fatty acids have been exchanged by a chemical process; 2) ethyl esters and 3) free fatty acids. Natural fish oils usually contain a balanced mixture of different fatty acids from the fish, while chemically modified products contain higher concentrations of EPA and DHA at the expense of other fatty acids and antioxidants (substances which inhibit oxidation, e.g. rancidity of fat). Chemically modified products with higher concentrations of EPA and DHA have not been shown to have a better effect than natural fish oils. On the contrary, several studies indicate that natural fish oils can have more favourable effects than chemically modified products.

Most fish oil products available today are unstable, i.e., they become rancid when exposed to air (Table 1), and after intake they induce consumption of antioxidants, such as vitamin E. This will lead to the formation of free radicals (molecules with unpaired electrons), which can cause cellular injury. There is no direct association, however, between the content of vitamin E in the fish oils and their stability (Table 1). Chemically modified fish oils are usually more unstable than natural fish oils (Table 1). The effects observed after intake of an unstable fish oil are the net effects of the positive actions of the omega-3 fatty acids and the negative results of the formation of free radicals. Most of our studies have been performed with a natural stable fish oil (Table 1).

In natural stable fish oil the antioxidant system of the fish has been restored

The living fish has a potent antioxidant system. After the death of the fish and during preparation of the fish oil, a major part of the antioxidants are lost, resulting in formation of free radicals. In the stable fish oil preparation the natural antioxidant system of the fish has been restored by the addition of a mixture of natural antioxidants.

Composition of the natural stable fish oil

The main omega-3 fatty acids of the natural, stable fish oil are EPA (18%) and DHA (12%). The stable fish oil also contains other omega-3 fatty acids such as 16:4, 18:3, 18:4, 20:4, 21:5, 22:4 and 22:5, in total about 8%. It also contains about 25% monounsaturated fatty acids. Further, it contains natural antioxidants, e.g. natural vitamin E in a unique, scientifically validated mixture and concentration.

This fish oil is stable both within and outside the body

Compared with other fish oils, both natural and chemically modified, this fish oil is much more stable when exposed to oxygen in the body or in test systems outside the body. Over a period of 3 weeks the peroxide value, a marker of rancidity of the fish oil, remains unchanged in the stable fish oil, which contains a special mixture of natural antioxidants. In contrast, marked rancidity is noted in an ordinary fish oil containing the same amount of fatty acids and an amount of vitamin E often used in ordinary fish oils.

Intake of "ordinary" fish oil (natural unstable) resulted in a decrease in vitamin E in the blood and increased malondialdehyde, a marker of free radical formation in the blood and in tissues such as the heart and the blood vessels. Such changes were not seen after intake of stable fish oil.

Natural stable fish oil has a neutral taste and is odourless – quite different from cod liver oil!

Ordinary (unstable) fish oils and especially chemically modified fish oils often have a poor, unpalatable taste. One way to test the stability of a fish oil in capsules is to bite the capsule and taste the oil. An unpalatable taste and an unpleasant odour reflect unstable properties of fish oil, whereas the stable fish oil has a neutral taste and is odourless.

Unfortunately many persons confuse fish oil, which is obtained from the muscles and fat tissue of the oily fish, with cod liver oil, which is obtained from the liver of cod. Cod liver oil has a different taste and is primarily used for supplementation of vitamins A and D. Many middle-aged or older people may remember the unpleasant taste of cod liver oil from their childhood and do not realise that fish oil is something quite different. Recently cod liver oil because of its high content of vitamin A has been suspected to induce fragile bones (osteoporosis).

The natural stable fish oil is free from toxic contaminants

The concentrations of heavy metals such as cadmium, copper, iron, mercury and lead are below the detection levels in the natural stable fish oil, as are pesticides such as DDT, DDE, HCB, PCB and lindane, due to a special purification technique. Unfortunately, many fish oils (Table 2) and most fish contain one or more of these toxic contaminants.

TABLE 2 Concentrations of Organochlorine Contaminants Present in Fish Oils (µg/L) °
	DDT	PCBs		DDT	PCBs
Fish oil 1	148	570	Fish oil 10	62	428
Fish oil 2	63	440	Fish oil 11	0*	10
Fish oil 3	0*	0*	Fish oil 12	0*	37
Fish oil 4	95	313	Fish oil 13	137	1055
Fish oil 5	0*	0*	Fish oil 14	0*	14
Fish oil 6	69	261	Fish oil 15	138	1050
Fish oil 7	40	212	Fish oil 16	0*	0*
Fish oil 8	119	990	Fish oil 17	58	915
Fish oil 9	40	1132	Stable Fish Oil	0*	0*
° Modified from Jacobs MN, Johnston PA. Organochlorine pesticides and PCB residues in pharmaceutical and industrial grade fish oil. Greenpeace Research Laboratories, technical note 05/95, 4th May, 1995. (Fish Oil 1-17) * Below the detection levels, 18 and 4.5 µm/L, respectively.

Stable fish oil has more favourable effects than ordinary (unstable) fish oils

In our studies the increased stability of stable fish oil was associated with more potent effects on various factors compared to ordinary, unstable fish oil (Table 3).

Cholesterol

LDL-cholesterol (the "bad" cholesterol), a major risk factor for coronary artery disease, was decreased by the stable fish oil, whereas ordinary fish oil did not have this effect. HDL-cholesterol (the "good" cholesterol) was increased by both oils in this particular study, but other studies have shown a larger increase after intake of the stable fish oil.

Triglycerides

Persons suffering from myocardial infarction often have high blood levels of triglycerides, a major risk factor for cardiovascular disease. Triglycerides contain three fatty acids bound to glycerol. Stable fish oil decreased the triglycerides markedly and to a greater extent than ordinary (unstable) fish oil. In fact no other compound known to date seems to be more effective in decreasing triglycerides.

Fibrinogen

Fibrinogen, a blood protein, is an important risk factor for cardiovascular disease. Fibrinogen is converted to fibrin, the main component in blood clots and thrombi, and a high level of blood fibrinogen increases the risk for atherosclerosis and establishment of thrombosis. Stable fish oil is one of the very few compounds available that will decrease the fibrinogen level in the blood.

Lipoprotein(a)

Lipoprotein(a) is one of the most important risk factors for heart disease. It is a lipoprotein with structural similarities to both LDL-cholesterol and plasminogen, an important protein in the fibrinolytic (blood clot dissolving) system. When lipoprotein(a) replaces plasminogen in the blood clot or thrombus, the risk of developing myocardial infarction is markedly increased. Lipoprotein(a) decreased after intake of natural stable fish oil. Few compounds other than fish oil have been shown to decrease the lipoprotein(a) level in the blood.

Stable fish oil does not increase blood sugar

Patients with diabetes would benefit from intake of omega-3 fatty acids for many reasons, one of which is to diminish the increased tendency to thrombus formation that is seen in diabetes. However, up to now many physicians have hesitated to give fish oil to these patients for the reason that ordinary fish oil is known to increase blood sugar (Fig 1). This may be due to the formation of free radicals in the pancreas, with decreased production of insulin. With stable fish oil this adverse effect is not observed (Fig 1), and stable fish oil can thus be given to diabetic patients, which is a major advantage. Unfortunately ordinary (unstable) fish oil can also induce an increase in blood sugar in persons without diabetes.

Fig 1

Stable fish oil and brain function

There are old sayings that "eating fish will make you intelligent" and that "fish is brain food". Recent studies have shown that this may well be true and that the reason lies in the omega-3 fatty acids, especially DHA, which are abundant in the brain as well as in fatty fish. An association between the brain content of DHA and mental capacity and health has recently been found.

Experimental studies have shown that intake of natural stable fish oil increases DHA in the brain. This fish oil also increases nitric oxide synthase, an important mediator of neurotransmission in the brain. These positive changes after intake of stable fish oil are much more pronounced than after intake of ordinary (unstable) fish oil (Fig 2). Children with low levels of omega-3 fatty acids have a lower overall mental capacity, especially, for example, in solving mathematical problems, and have difficulty in getting to sleep and getting up in the morning. Studies on intellectual functions have surprisingly shown that intake of fish oil containing DHA increases the intellectual capacity as early as two hours after the intake.

Fig 2

It has been found important, however, that the fish oil is stable. If it is unstable the beneficial effects may be lost. Fish oil may also have a salutory effect on the attention-deficit/hyperactive disorder in children. Further, it has been shown to have an effect on depression, including post partum depression, and on cardiovascular and Alzheimer's dementia. It is well known that depression is associated with a diminished concentration of serotonin in the brain and that the serotonin concentration is associated with the plasma levels of omega-3 fatty acids, especially DHA. It has also been shown that intake of omega-3 fatty acids, particularly EPA, is associated with a reduction in the severity of symptoms in schizophrenia.

All these studies taken together suggest that fish oil has important effects on brain function.

Fish oil and joint disease

Natural stable fish oil has a better effect on joint stiffness than ordinary (unstable) fish oil (Fig 3). As rheumatoid arthritis is very uncommon among the Eskimos, fish oil treatment has been tried in this condition. Natural fish oil has been shown to decrease pain and tenderness and the need for antiinflammatory drugs. It often takes several months for the effects of the fish oil to appear and certain persons may need a larger dose of fish oil than normally to obtain the best effect, e.g. 10 ml daily of natural stable fish oil.

Fig 3

Fish oil and skin disease

Intake of omega-3 fatty acids makes the skin more supple and more elastic. Also, skin problems such as dry skin, eczema and psoriasis can be improved. The improvements are due to an effect on the elasticity of the cellular walls and eicosanoids, a hormone-like substances with important effects on different bodily functions.

Clinical documentation of natural stable fish oil

Natural fish oil is by far the best documented natural pharmaceutical or food supplement available today. During a recent 10 month period 293 articles about fish oil were published in well known medical journals, as against six articles concerning ginkgo biloba and 16 about ginseng. The effect of natural stable fish oil has been proven in many different scientific studies (see reference list). In these studies the stable fish oil was given to patients for up to 8 years without any adverse effects or loss of effects. Most studies were randomised, with a double-blind crossover design, which means that the participants were assigned to different groups by lot; the same person was given active oil and placebo oil during different periods, and neither the participants nor the researchers knew the identity of the oil.

The effects seem to increase with the length of the treatment period. Thus, the reductions in triglycerides, total cholesterol, fibrinogen and diastolic blood pressure were greater after 6 months than after 1 or 3 months of intake of stable fish oil (Figs 4-5).

Fig 4

Fig 5

Recommended intake of stable fish oil

The recommended intake is 5 ml (one 0.2 oz. spoon) of fluid stable fish oil daily or 3 capsules 1-3 times daily with meals for maintenance of a healthy circulation, supple joints and healthy skin. Higher doses can be used for the treatment of specific disease symptoms upon the advice of a physician. Some patients use 10 ml daily without any side effects. Three capsules daily corresponds to a dose of natural fish oil which has been shown to decrease mortality from cardiovascular disease. Long-term treatment with a lower dose seems to have the same effect as treatment with a higher dose for a shorter period of time.

This fish oil, being natural, stable and pure, would probably be an ideal source of omega-3 fatty acids for pregnant women, but so far no controlled studies have been conducted in this category of subjects. There is also an increased need for omega-3 fatty acids during lactation.

Studies on natural stable fish oil

1. Haglund O, Luostarinen R, Vessby B, Wibell, L, Sandhagen B, Saldeen T. Effect of omega-3 fatty acids on blood lipids and blood rheology. (Swe.) Hygiea 97: 316, 1988.
2. Luostarinen R, Haglund O, Wallin R, Saldeen T. Influence of omega-3 polyunsaturated fatty acids (PUFA) on leukocyte function. (Swe.) Hygiea 97: 316, 1988.
3. Haglund O, Wallin R, Luostarinen R, Alving B, Sandhagen B, Saldeen T. Effect of a new fluid fish oil concentrate, Eskimo-3, on triglycerides, cholesterol, blood pressure, fibrinogen and whole blood viscosity. (Swe.) Hygiea 98: 324-325, 1989.
4. Haglund O, Wallin R, Luostarinen R, Saldeen T. Effects of a new fluid fish oil concentrate, Eskimo-3, on triglycerides, cholesterol, fibrinogen and blood pressure. Journal of Internal Medicine 227: 347-353,1990.
5. Haglund O, Wallin R, Luostarinen R, Saldeen T. Effects of a new fluid fish oil concentrate, Eskimo-3, on triglycerides, cholesterol, fibrinogen and blood pressure. Lipid Digest 8: 29-31, 1990.
6. Haglund O, Landelius J, Luostarinen R, Alving B, Saldeen T. Fish oil improves arterial compliance. (Swe.) Hygiea 99: 303, 1990.
7. Haglund O, Luostarinen R, Wallin R, Wibell L, Saldeen T. Effect of fish oil with different amounts of vitamin E on blood lipids, fibrinogen, glucose and malondialdehyde. (Swe.) Hygiea 99: 303, 1990.
8. Haglund O, Luostarinen R, Wallin R, Alving B, Wibell L, Hambreus L, Saldeen T. Effect of fish oil with and without supplementation with vitamin B. (Swe.) Hygiea 99: 304, 1990.
9. Haglund O, Luostarinen R, Wallin R, Wibell L, Saldeen T. Effect of fish oil on fibrinolysis, fibrinogen and lipoprotein(a) (Lp (a)). (Swe.) Hygiea 99: 304-305, 1990.
10. Haglund O, Luostarinen R, Wallin R, Wibell L, Saldeen T. The effects of fish oil on triglycerides, cholesterol, fibrinogen and malondialdehyde in humans supplemented with vitamin E. Journal of Nutrition 121: 165-169, 1991.
11. Haglund O, Saldeen T, Luostarinen R, Wallin R. Fat fish and natural fish oil prevent cardiac death. Some possible mechanisms. (Swe.) Hygiea 100: 321-322, 1991.
12. Lawson D, Mehta J, Saldeen K, Mehta P, Haglund O, Saldeen T. Fish oil relaxes blood vessels and increases EDRF (nitric oxide). (Swe.) Hygiea 100: 318, 1991.
13. Haglund O, Luostarinen R, Wallin R, Saldeen T. Effects of fish oil on triglycerides, cholesterol, lipoprotein(a), atherogenic index and fibrinogen. Influence of degree of purification of the oil. Nutrition Research 12: 455-468, 1992.
14. Haglund O, Luostarinen R, Alving B, Wallin R, Saldeen T. Effect of fish oil on triglycerides, cholesterol, lipoprotein(a), atherogenic index and fibrinogen. Importance of degree of purification of the oil. (Swe.) Hygiea 101: 352, 1992.
15. Luostarinen R, Siegbahn A, Saldeen T. Effect of dietary fish oil supplemented with different doses of vitamin E on neutrophil chemotaxis in healthy volunteers. Nutrition Research 12: 1419-1430,1992.
16. Luostarinen R, Siegbahn A, Saldeen T. Effect of fish oil with different contents of vitamin E on chemotaxis. (Swe.) Hygiea 101: 351, 1992.
17. Luostarinen R, Saldeen T. Effect of fish oil on superoxide production in leukocytes. (Swe.) Hygiea 101: 352, 1992.
18. Saldeen T, Yang B, Nichols W, Mehta J. Effect of fish oil on myocardial ischaemia and reperfusion. (Swe.) Hygiea 101: 351-352,1992.
19. Saldeen T, Haglund O, Luostarinen R. Fish oil and nitric oxide. (Swe.) Hygiea 101: 354, 1992.
20. Wallin R, Saldeen T. Oxidation of n-3 fatty acids. (Swe.) Hygiea 101: 352,1992.
21. Haglund O, Hamfelt A, Hambraeus L, Saldeen T. Effects of fish oil supplemented with pyridoxine and folic acid on homocysteine, atherogenic index, fibrinogen and plasminogen activator-1 in man. Nutrition Research 13: 1351-1365, 1993.
22. Haglund O. Effects of fish oil on risk factors for cardiovascular disease. Compr. Sum. Upps. Diss. Med. Fac. 428,1993. Doctoral thesis, Uppsala University.
23. Haglund O, Wallin R, Wretling 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 Univ. Ups. 428; Vo1-22,1993.
24. Haglund O. Effects of fish oil on risk factors for cardiovascular disease. Ups. J. Med. Sci. 98: 89-148,1993.
25. Luostarinen R, Wallin R, Alving B, Saldeen T. Vitamin E prevents increase in blood glucose after fish oil treatment. (Swe.) Hygiea 102: 343-344,1993.
26. Luostarinen R, Wallin R, Jokela R, Saldeen T. Effect of fish oil with different concentrations of vitamin E on blood cholesterol and malondialdehyde in the heart. (Swe.) Hygiea 102: 344, 1993.
27. Yang BC, Saldeen TGP, Bryant JL, Nichols WW, Mehta JL. Long-term dietary fish oil supplementation protects against ischaemia reperfusion-induced myocardial dysfunction in isolated rat hearts. American Heart Journal 126: 1287-1292, 1993.
28. Yang BC, Saldeen TGP, Nichols WW, Mehta JL. Dietary fish oil supplementation attenuates myocardial dysfunction caused by global ischaemia and reperfusion in isolated rat hearts. Journal of Nutrition 123: 2067-2074, 1993.
29. Haglund O, Mehta JL, Saldeen T. Effects of fish oil on some parameters of fibrinolysis and lipoprotein (a) in man. American Journal of Cardiology 7: 189-192, 1994.
30. Haglund O, Åslund A, Luostarinen R, Saldeen T. Importance of base-line value and changes in n-3 fatty acids in plasma for the effect of fish oil on blood lipids. (Swe.) Hygiea 103: 347, 1994.
31. Luostarinen R, Alving B, Saldeen T. (n-3) fatty acids increase superoxide dismutase (SOD) activity in heart muscle. Effect of prostacyclin/thromboxane ratio. (Swe.) Hygiea 103: 347-348, 1994.
32. Saldeen T, Luostarinen R, Haglund O, Wallin R. N-3 fatty acids and ischaemic heart disease. Lipid Forum 1994, Bergen, Norge, 20-34.
33. Saldeen T, Wallin R, Alving B, Marklinder I. Effect of fish oil in bread on fatty acids in plasma phospholipids and on serum triglycerides. In Lambertsen G. (Ed.): Lipids from the sea. Lipidforum. Bergen, Norge 1994: 77.
34. Saldeen T, Luostarinen R, Haglund O, Wallin R. N-3 fatty acids and sudden cardiac death. (Swe.) Hygiea 103: 347, 1994.
35. Saldeen T, Wallin R, Alving B, Marklinder I. Effect of a small dose of fish oil as substitution for margarine in bread. (Swe.) Hygiea 103: 348, 1994.
36. Saldeen T, Luostarinen R, Haglund O, Wallin R, Mehta J. N-3 fatty acids and cardiovascular disease. Scientific Conference on Omega-3 Fatty Acids in Nutrition, Vascular Biology and Medicine. Houston, Texas 1994: 30.
37. Engström K, Haglund O, Saldeen T. Effect of fish oil alone and in combination with evening primrose oil on prostanoids. (Swe.) Hygiea 104: 361, 1995.
38. Engström K, Luostarinen R, Saldeen T. Production of thromboxane, prostacyclin and leukotriene B in whole blood after supplementation with stable fish oil. (Swe.) Hygiea 104: 361-362, 1995.
39. Haglund O, Mehta JL, Saldeen T. Effect of fish oil on some parameters of fibrinolysis. In: Fibrinolysis in disease. The malignant process. Interventions in thrombogenic mechanisms and novel treatment modalities. CRC Press, Boca Raton, 1995: 102-109.
40. Jokela R, Engström K, Alving B, Wallin R, Saldeen T. Effect of fish oil with and without Pufanox on prostanoids, lipid peroxidation and blood glucose. (Swe.) Hygiea 104: 361, 1.995.
41. Luostarinen R, Wallin R, Wibell L, Saldeen T. Vitamin E supplementation counteracts the fish oil induced increase of blood glucose in humans. Nutrition Research 15: 953-968, 1995.
42. Luostarinen R. Studies on (n-3) polyunsaturated fatty acids. With special reference to cardiovascular disease. Compr. Sum. Upps. Diss. Med. Fac. 558, 1995. Doctoral thesis, Uppsala University.
43. 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. Bi & Gi Publishers, Verona, Springer Verlag, London, 1995: 125-139.
44. Saldeen T, Luostarinen R, Engström K, Wallin R. Importance of extra vitamin E for the effects of a stabilised fish oil in humans. Lipidforum, Bergen, Norge 1995: 43-46.
45. Alving B, Engström K, Wallin R, Saldeen T. Effect of eight years intake of stable fish oil. (Swe.) Hygiea 105: 373, 1996.
46. Engström K, Luostarinen R, Saldeen T. Whole blood production of thromboxane, prostacyclin and leukotriene B after dietary fish oil supplementation in men. Effect of vitamin E4. Prostaglandins, Leukotrienes and Essential Fatty Acids. 54: 419-425, 1996.
47. Engström K, Alving B, Wallin R, Saldeen T. Effect of a combination of a low dose of acetylsalicylic acid and stable fish oil on eicosanoids. (Swe.) Hygiea 105: 373, 1996.
48. Engström K, Alving B, Wallin R, Saldeen T. Stable fish oil has better effect on cholesterol and joint stiffness than ordinary fish oil. (Swe.) Hygiea 105: 373, 1996.
49. Engström K, Alving B, Wallin R, Saldeen T. Effect of addition of stable fish oil to caviar on blood lipids (Swe.) Hygiea 105: 373, 1996.
50. Engstr"m K, Saldeen A-S, Rönneberg R, Wallin R, Mehta J, Saldeen T. Effect of EPA and DHA on blood vessel relaxation. (Swe.) Hygiea 105: 374, 1996.
51. Luostarinen R, Saldeen T. Dietary fish oil decreases superoxide generation by human neutrophils: relation to cyclooxygenase pathway and lysosomal enzyme release. Prostaglandins, Leukotrienes and Essential Fatty Acids. 55: 167-172, 1996.
52. Saldeen A-S, Engström K, Rönneberg R, Wallin R, Mehta J, Saldeen T. Effect of stable and ordinary fish oil containing high concentrations of EPA and DHA, respectively, on nitric oxide synthase and DHA content in the brain. (Swe.) Hygiea 105: 373, 1996.
53. Yang B. Protective effects of platelets and stable fish oil against ischaemia/reperfusion injury: Role of nitric oxide and antioxidants. Compr. Sum. Upps. Diss. Med. Fac. 634, 1996. Doctoral thesis, Uppsala University.
54. Yang B, Mehta J, Saldeen T. Effect of platelets and stable fish oil on ischaemia/reperfusion injury: Importance of nitric oxide and antioxidants. (Swe.) Hygiea 105: 372-373, 1996.
55. Haglund O, Wallin R, Wretling 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. J. Nutr. Biochem. In press.
56. Luostarinen R, Wallin R, Saldeen T. Dietary (n-3) fatty acids increase superoxide dismutase activity and decrease thromboxane production in the heart. Nutrition Research. 17: 163-176, 1997.
57. Saldeen T, Wallin R, Alving B, Marklinder I. Effect of a small dose of fish oil substituted for margarine in bread on plasma phospholipid fatty acids and serum triglycerides. Nutrition Research. In press.