The Many Uses of Omega-3 Fatty Acids

References

Eicosapentaenoic acid (EPA) and docosahexanaeoic acid (DHA) are omega-3 essential fatty acids (EFAs). Omega-3 EFA supplements are mostly derived from coldwater species of fish like salmon, sardines, herring and mackerel; as well as from a few vegetarian sources, such as flaxseed oil. There are many therapeutic applications for omega-3 EFAs, primarily due to their cardiovascularenhancing and anti-inflammatory benefits. Research has shown that the cardiovascular benefits of omega-3 EFAs include reducing the risk of atherosclerosis, modifying cholesterol levels (i.e., increasing “good” HDL cholesterol, while decreasing “bad” LDL cholesterol), decreasing triglycerides and decreasing high blood pressure. Omega-3 EFAs have also been shown to block the production of certain inflammatory chemicals in the body. Consequently, studies have demonstrated the ability of omega-3 EFAs to reduce inflammation in such disorders as rheumatoid arthritis, asthma, colitis, Crohn’s disease and lupus. In addition, omega-3 EFAs may reduce the symptoms of other disorders including angina, migraine headaches, psoriasis and tinnitus.

Most fish oil supplements come in a mixture of 18 percent EPA and 12 percent DHA. Therefore, in 1,000 mg of fish oil there would be 180 mg EPA and 120 mg DHA. However, it makes sense to seek out more concentrated preparations, which minimize the amount of fish oil consumed helping to prevent gastric reflux. Products are available in the 375 mg EPA and 250 mg DHA range, providing 625 mg of total omega-3s. The doses recommended in the following conditions are based on the use of a supplement providing 625 mg of total omega-3s.

People who take omega-3 EFAs may also need to take vitamin E to protect the oil from oxidative damage in the body.¹ The vitamin E can be included with the omega-3 EFA, or as a separate supplement.

There is so much research supporting supplementation with omega-3 EFAs in atherosclerosis that it is unnecessary to go beyond research conducted in just the last few years to make the case. These studies have clearly shown that omega-3 EFAs can reduce risk factors for atherosclerosis,^2,3 as well as slowing the progression of the disease itself.^4,5 As a matter of fact, The Physicians Health Study (22,071 doctors) suggests fish oils can reduce a man’s risk of dying from a heart attack by 80 percent.⁶ Likewise, the Nurses Health Study (84,688 female nurses), found omega-3 EFAs can cut a woman’s risk of death by heart attack by 33 percent.⁷

Omega-3s are actually able to lower levels of certain genetically predisposed substances that are relevant to atherosclerosis.⁸ Another related benefit is that omega-3s reduce the potential for blood clots in atherosclerosis patients.⁹ An effective dose would be one to three capsules daily.

One of the main mechanisms by which omega-3s work is by affecting cholesterol. Including fish as a regular part of the diet has been shown to increase HDL cholesterol,¹⁰ and is linked to a reduced risk of heart disease in the majority of studies.¹¹ Fish not only contains very little saturated fat, but its oils are rich in the omega-3 EFAs that appear to protect against heart disease.¹² Of course omega-3s are available in supplemental form, and research has shown supplementation with omega-3 EFAs lowers total cholesterol, LDL cholesterol and triglycerides, while increasing HDL cholesterol.^13,14 An effective dose would be five capsules daily.

Also in the realm of cardiovascular health is the impact of omega-3s on high blood pressure. According to a meta-analysis of 31 studies, the omega-3s found in fish oil effectively lower blood pressure.15 This effect was dependent on the amount of omega-3s used, with best results occurring in studies using very high doses, around 15 g/d. Obtaining 15 grams of omega-3s would generally require consuming an enormous number of capsules! Such huge doses would not be a reasonable addition to a dietary supplement program for most people. Another possibility is to use the higher potency omega-3 EFAs discussed earlier, which could yield 3 g/d; research has shown significant reductions in blood pressure occurred at these lower intakes, just not as impressively as with the higher doses.

Finally, omega-3 EFAs have been studied in the treatment of angina. Some research indicates that 3 g or more of omega-3 EFAs three times per day (providing a total of about 3 g EPA and 2 g DHA) have reduced chest pain as well as the need for nitroglycerin, a common medication used to treat angina.¹⁶ However, other research did not confirm these benefits.¹⁷ Based upon the research showing results, an effective dose would be eight capsules daily; however, people wishing to take this high dose should first consult with a nutritionally oriented physician.

To understand why omega-3 EFAs have anti-inflammatory benefits, it is important to understand how inflammation works. Many factors contribute to the complex course of inflammatory reactions. One important contributing factor is the fatty acid, arachidonic acid (AA). AA can be converted via an enzymatic process into pro-inflammatory substances, especially one called prostaglandin 2 (PG2). In states of inflammation, it seems omega-3 EFAs are able to compete with AA for enzymatic metabolism, which results in less production of PG2. Generally, for inflammatory conditions, one to two capsules daily appears to mitigate the inflammatory response.

Well-controlled clinical studies have clearly demonstrated consumption of omega-3 EFAs results in improvements in rheumatoid arthritis (RA) sufferers.¹⁸ As a matter of fact, a comprehensive review of medical literature by a board certified rheumatologist revealed treatment with omega-3 EFAs was associated with improvement in outcome measures in RA, and was able to help decrease the long-term requirements for nonsteroidal anti-inflammatory drugs (e.g., aspirin, ibuprofen) in some circumstances.¹⁹ Furthermore, an expert workshop reviewing the health effects of omega-3s concluded these natural substances helped alleviate the symptoms of RA.²⁰ It should be noted these omega-3 EFA-related benefits were not limited to adult RA sufferers. A study conducted in the Czech Republic found children with chronic juvenile arthritis were able to decrease their ibuprofen consumption by 17.3 percent over a period of five months when treated with a high omega-3 EFA diet.²¹

The same inflammatory mechanism previously described holds true for the inflammatory process involved in asthma, and the beneficial role of omega-3 EFAs in treating this disorder. This was demonstrated in a clinical trial where omega-3s significantly decreased bronchial hyper-reactivity in patients suffering from seasonal asthma due to airborne allergens.²² Similar research with omega-3 EFAs in asthma has shown a reduction of symptoms.^23,24,25

There is a significant amount of research documenting the effectiveness of omega-3 EFAs in the treatment of inflammatory bowel conditions. For example, in two randomized, double blind, placebo-controlled, crossover trials, administration of omega-3 EFAs resulted in significant improvements in colitis patients; including the ability to reduce or eliminate use of anti-inflammatory drugs.26,27 Other studies have shown similar beneficial results in colitis with omega-3 EFAs.^28,29,30 Significantly lower levels of the omega-3s have also been found in Crohn’s disease patients.³¹ Other research has suggested that a reduction in omega-3s may be relevant to the activity of the disease.³² In fact, in animal research, supplementation with omega-3 EFAs markedly reduced bowel lesions after 30 days, and inflammation and ulceration in the bowel were almost absent by day 50.³³

Supplementation with omega-3 EFAs has prevented autoimmune lupus in animal research.³⁴ In a double blind study, 20 g/d of fish oil combined with a low fat diet led to improvement in 14 of 17 people with systemic lupus erythematosus in 12 weeks.³⁵ Smaller amounts of fish oil have led to only temporary improvement in other double blind research.³⁶ If the higher potency fish oil supplement is used, then the 20 g dose could be halved to 10 g. This would still require, however, the consumption of 15 to 18 capsules daily. People wishing to take such a large amount of fish oil should first consult with a nutritionally oriented physician.

Omega-3 EFAs have benefits in other health conditions as well. Research indicates omega-3s may reduce the symptoms of migraine headaches.^37,38 The omega-3s in fish oil may help due to their effects in modifying prostaglandins,³⁹ hormone-like substances made by the body, and/or due to the platelet-stabilizing and antivasospastic actions.⁴⁰ One study used 1 g of fish oil per 10 pounds of body weight. This would be a tremendous amount of fish oil to consume; even if higher potency omega-3 supplements were used, the number of capsules consumed at this rate may be prohibitive. Some researchers have suggested that heart disease patients could benefit from low doses (1 g/d to 6 g/d) of fish oils; similar benefits might be achieved by migraine patients at that level.

Moving on to skin health, in a double blind study, fish oil (10 g/d) was found to improve the skin lesions of psoriasis.⁴¹ In another study, supplementing with 3.6 g/d of purified EPA reduced the severity of psoriasis after two to three months.^42,43 Another possibility is topical use. One study showed applying a preparation containing 10 percent fish oil directly to psoriatic lesions twice daily resulted in improvement after seven weeks.⁴⁴ Supplementing with fish oil also may help prevent the increase in blood levels of triglycerides that occurs as a side effect of certain drugs used to treat psoriasis (e.g., etretinate and acitretin).⁴⁵

November 2004 Health Supplement Retailer
"The Many Uses of Omega-3 Fatty Acids" References

1. Haglund O et al. "The effects of fish oil on triglycerides, cholesterol, fibrinogen and malondialdehyde in humans supplemented with vitamin E." J Nutr. 121, 2:165-69, 1991. www.nutrition.org

2. Johansen O et al. "The effect of supplementation with omega-3 fatty acids on soluble markers of endothelial function in patients with coronary heart disease." Arterioscler Thromb Vasc Biol. 19, 7:1681-6, 1999. http://atvb.ahajournals.org

3. Enikeeva NA et al. "[Atherosclerosis: feasibility of non-pharmacological correction of some risk factors]." Klin Med (Mosk). 77, 3:25-8, 1999.

4. von Schacky C et al. "The effect of dietary omega-3 fatty acids on coronary atherosclerosis. A randomized, double-blind, placebo-controlled trial." Ann Intern Med. 130, 7:554-62, 1999. www.annals.org

5. Sucic M, Katica D, Kovacevic V. "Effect of dietary fish supplementation on lipoprotein levels in patients with hyperlipoproteinemia." Coll Antropol. 22. 1:77-83, 1998.

6. Albert CM et al. "Blood levels of long-chain n-3 fatty acids and the risk of sudden death." N Engl J Med. 346, 15:1113-8, 2002. http://content.nejm.org

7. Hu FB et al. "Fish and omega-3 fatty acid intake and risk of coronary heart disease in women." JAMA. 287, 14:1815-21, 2002. www.jama.com

8. Baumann KH et al. "Dietary omega-3, omega-6, and omega-9 unsaturated fatty acids and growth factor and cytokine gene expression in unstimulated and stimulated monocytes. A randomized volunteer study." Arterioscler Thromb Vasc Biol. 19, 1:59-66, 1999. http://atvb.ahajournals.org

9. Seljeflot I et al. "Procoagulant activity and cytokine expression in whole blood cultures from patients with atherosclerosis supplemented with omega-3 fatty acids." Thromb Haemost. 81, 4:566-70, 1999.

10. Santos MJ et al. "Influence of dietary supplementation with fish on plasma total cholesterol and lipoprotein cholesterol fractions in patients with coronary heart disease." J Nutr Med. 3:107-15, 1992.

11. Kromhout D, Bosschieter EB, Coulander CdL. "The inverse relation between fish consumption and 20-year mortality from coronary heart disease." N Engl J Med. 312:1205-9, 1985. http://content.nejm.org

12. Albert CM et al. "Fish consumption and the risk of sudden death in the Physicians’ Health Study." Circulation 94, Suppl 1:I-578 [abstract #3382], 1996. http://circ.ahajournals.org/

13. Ibid.

14. Zak A, Zeman M, Tvrzicka E. "[Effect of fish oils on plasma lipid risk factors and esterified fatty acids in primary hyperlipoproteinemia]." Sb Lek. 98, 3:213-24, 1997.

15. Morris MC, Sacks F, Rosner B. "Does fish oil lower blood pressure? A meta-analysis of controlled trials." Circulation. 88, 2:523-33, 1993. http://circ.ahajournals.org/

16. Saynor R, Verel D, Gillott T. "The long-term effect of dietary supplementation with fish lipid concentrate on serum lipids, bleeding time, platelets and angina." Atherosclerosis. 50, 1:3-10, 1984. www.elsevier.com/locate/atherosclerosis

17. Mehta JL et al. "Dietary supplementation with omega-3 polyunsaturated fatty acids in patients with stable coronary heart disease. Effects on indices of platelet and neutrophil function and exercise performance." Am J Med. 84, 1:45-52, 1988. www-east.elsevier.com/ajm/menu.html

18. Alexander JW. "Immunonutrition: the role of omega-3 fatty acids." Nutrition. 14, 7-8:627-33, 1998. www.elsevier.com/locate/nut

19. Ariza-Ariza R, Mestanza-Peralta M, Cardiel MH. "Omega-3 fatty acids in rheumatoid arthritis: an overview." Semin Arthritis Rheum. 27, 6:366-70, 1998.

20. de Deckere EA et al. "Health aspects of fish and n-3 polyunsaturated fatty acids from plant and marine origin." Eur J Clin Nutr. 52, 10:749-53, 1998. www.naturesj.com/ejcn

21. Vargova V et al. "[Will administration of omega-3 unsaturated fatty acids reduce the use of nonsteroidal antirheumatic agents in children with chronic juvenile arthritis?]" Cas Lek Cesk. 137, 21:651-3, 1998.

22. Villani F et al. "Effect of dietary supplementation with polyunsaturated fatty acids on bronchial hyperreactivity in subjects with seasonal asthma." Respiration. 65, 4:265-9, 1998.

23. Broughton KS et al. "Reduced asthma symptoms with n-3 fatty acid ingestion are related to 5-series leukotriene production." Am J Clin Nutr. 65, 4:1011-7, 1997. www.ajcn.org

24. Masuev KA. "[The effect of polyunsaturated fatty acids on the biochemical indices of bronchial asthma patients]." Ter Arkh. 69, 3:33-5, 1997.

25. Masuev KA. "[The effect of polyunsaturated fatty acids of the omega-3 class on the late phase of the allergic reaction in bronchial asthma patients]." Ter Arkh. 69, 3:31-3, 1997.

26. Stenson WF et al. "Dietary supplementation with fish oil in ulcerative colitis." Ann Intern Med. 116, 8:609-14, 1992. www.annals.org

27. Aslan A, Triadafilopoulos G. "Fish oil fatty acid supplementation in active ulcerative colitis: a double blind, placebo-controlled, crossover study." Am J Gastroenterol. 87, 4:432-7, 1992. www.amjgastro.com

28. Almallah YZ et al. "Distal procto-colitis, natural cytotoxicity and essential fatty acids." Am J Gastroenterol. 93, 5:804-9, 1998. www.amjgastro.com

29. Salomon P, Kornbluth AA, Janowitz HD. "Treatment of ulcerative colitis with fish oil n-3-omega-fatty acid: an open trial." J Clin Gastroenterol. 12, 2:157-61, 1990.

30. McCall TB et al. "Therapeutic potential of fish oil in the treatment of ulcerative colitis." Aliment Pharmacol Ther. 3, 5:415-24, 1989.

31. Geerling BJ et al. "Fat intake and fatty acid profile in plasma phospholipids and adipose tissue in patients with Crohn's disease, compared with controls." Am J Gastroenterol. 94, 2:410-7, 1999. www.amjgastro.com

32. Kuroki F et al. "Serum n3 polyunsaturated fatty acids are depleted in Crohn's disease." Dig Dis Sci. 42, 6:1137-41, 1997. www.kluweronline.com/issn/0163-2116/current

33. Vilaseca J et al. "Dietary fish oil reduces progression of chronic inflammatory lesions in a rat model of granulomatous colitis." Gut. 31, 5:539-44, 1990. http://gut.bmjjournals.com

34. Kelley VE et al. "A fish oil diet rich in eicosapentaenoic acid reduces cyclooxygenase metabolites, and suppresses lupus in MRL-lpr mice." J Immunol. 134:1914-19, 1985.

35. Walton AJ et al. "Dietary fish oil and the severity of symptoms in patients with systemic lupus erythematosus." Ann Rheum Dis. 50, 7:463-66, 1991. http://ard.bmjjournals.com/

36. Westberg G, Tarkowski A. "Effect of MaxEPA in patients with SLE. A double-blind, crossover study." Scand J Rheumatology. 19, 2:137-43, 1990.

37. McCarren T et al. Am J Clin Nutr. 41, 4:874, 1985. www.ajcn.org

38. Glueck CJ et al. Am J Clin Nutr. 43, 4:710, 1986. www.ajcn.org

39. Gibson RA. "The effect of diets containing fish and fish oils on disease risk factors in humans." Aust NZ J Med. 18, 5:713-22, 1988.

40. McCarty MF. "Magnesium taurate and fish oil for prevention of migraine." Med Hypotheses. 47, 6:461-6, 1996. www.harcourt-international.com/journals/mehy

41. Bittiner SB et al. "A double-blind, randomised, placebo-controlled trial of fish oil in psoriasis." Lancet. 1, 8582:378-80, 1988. www.thelancet.com

42. Kojima T et al. "Long-term administration of highly purified eicosapentaenoic acid provides improvement of psoriasis." Dermatologica. 182, 4:225-30, 1991.

43. Kojima T et al. "Effect of highly purified eicosapentaenoic acid on psoriasis." J Am Acad Dermatol. 21, 1:150-51, 1989. www.eblue.org

44. Dewsbury CE, Graham P, Darley CR. "Topical eicosapentaenoic acid (EPA) in the treatment of psoriasis." Br J Dermatol. 120, 4:581-84, 1989. www.medscape.com/viewpublication/1004_index

45. Ashley JM et al. "Fish oil supplementation results in decreased hypertriglyceridemia in patients with psoriasis undergoing etretinate or acitretin therapy." J Am Acad Dermatol. 19, 1 Pt. 1:76-82, 1988. www.eblue.org

Share this article: Email, Slashdot, Digg, Del.icio.us, Yahoo!MyWeb, Windows Live Favorites, Furl
Add this article feed to: RSS, My Yahoo, Newsgator, Bloglines

Read Comments [0]