Omega-3 fatty acids have been found to play a role in atherosclerosis and peripheral arterial disease (PAD). It is thought that both EPA and DHA improve plaque stability, decrease endothelial activation, and improve vascular permeability, thereby decreasing the chance of experiencing a cardiovascular event (41). It was found that EPA supplementation is associated with significantly higher amounts of EPA in the carotid plaque than placebo (P < 0.0001), which may lead to decreased plaque inflammation and increased stability (42). PAD, a manifestation of atherosclerosis, is characterized by buildup of plaque in the arteries of the leg and can eventually lead to complete blockage of the arteries. EPA+DHA supplementation has been shown to improve endothelial function in patients with PAD by decreasing plasma levels of soluble thrombomodulin from a median value of 33.0 μg/L to 17.0 μg/L (P = 0.04) and improve brachial artery flow–mediated dilation from 6.7% to 10.0% (P = 0.02) (43). Patients who had PAD and were supplemented with EPA experienced a significantly lower major coronary event HR than those who did not take EPA (HR: 0.44; 95% CI: 0.19–0.97; P = 0.041) (44).
Heart disease. Eating fish can be effective for keeping people with healthy hearts free of heart disease. People who already have heart disease might also be able to lower their risk of dying from heart disease by eating fish. The picture is less clear for fish oil supplements. For people who already take heart medications such as a "statin" and those who already eat a decent amount of fish, adding on fish oil might not offer any additional benefit.
Omega-3 is a group of long-chain polyunsaturated fatty acids, perhaps most notably found in fatty fish. As science parses the biological actions of nutrients, it turns out that omega-3 fats do many good things for the body and the brain. Known as an "essential" fatty acid, meaning the body must take it in from food sources, omega-3 is important to human metabolism.
Hamazaki, K., Syafruddin, D., Tunru, I. S., Azwir, M. F., Asih, P. B., Sawazaki, S., and Hamazaki, T. The effects of docosahexaenoic acid-rich fish oil on behavior, school attendance rate and malaria infection in school children--a double-blind, randomized, placebo-controlled trial in Lampung, Indonesia. Asia Pac.J Clin Nutr 2008;17(2):258-263. View abstract.
So for those people who will not eat liver, cod liver oil on a daily basis can be a very good way of getting that. And you do benefit from the omega-3 fatty acids, and with the cod liver oil, it may even be unimportant to eat fish if you’re getting the cod liver oil, although it’s still better to focus on the fish, the egg yolks, and just add some of the cod liver oil.
Gajos, G., Zalewski, J., Rostoff, P., Nessler, J., Piwowarska, W., & Undas, A. (2011, May 26). Reduced thrombin formation and altered fibrin clot properties induced by polyunsaturated omega-3 fatty acids on top of dual antiplatelet therapy in patients undergoing percutaneous coronary intervention (OMEGA-PCI Clot). Arteriosclerosis, Thrombosis, and Vascular Biology 111.228593. Retrieved from
Macchia, A., Levantesi, G., Franzosi, M. G., Geraci, E., Maggioni, A. P., Marfisi, R., Nicolosi, G. L., Schweiger, C., Tavazzi, L., Tognoni, G., Valagussa, F., and Marchioli, R. Left ventricular systolic dysfunction, total mortality, and sudden death in patients with myocardial infarction treated with n-3 polyunsaturated fatty acids. Eur.J.Heart Fail. 2005;7(5):904-909. View abstract.
Schilling, J., Vranjes, N., Fierz, W., Joller, H., Gyurech, D., Ludwig, E., Marathias, K., and Geroulanos, S. Clinical outcome and immunology of postoperative arginine, omega-3 fatty acids, and nucleotide-enriched enteral feeding: a randomized prospective comparison with standard enteral and low calorie/low fat i.v. solutions. Nutrition 1996;12(6):423-429. View abstract.
To reach the required dose of EPA for treating certain conditions such as depression, CVD or CFS/ME you would need to take approximately 1-2 grams of ‘free EPA’ daily. Even with a concentrated omega-3 fish oil supplement, offering 180 mg excess EPA over DHA, this would require 10-20 capsules daily – significant in terms of volume and cost, and not efficient in terms of uptake in the body as our capacity for fat absorption is limited. The most effective and efficient way to ensure high EPA uptake in the body rapidly is to supplement with pure EPA for a minimum of 3-6 months.
The GISSI-Prevenzione trial40 showed similar findings. In this open-label trial, 11,324 post-MI patients were followed for 3.5 years after randomization to either 1 g/d of omega-3 FA, vitamin E, both, or none. In the 2836 patients assigned to only omega-3 FA, the primary end point of death, nonfatal MI or stroke, was reduced by 10%. This decreased risk occurred despite a minimal triglyceride-lowering effect because of the relatively low dose of omega-3 FA. Of note, the GISSI-Prevenzione trial was done prior to the pervasive use of lipid-lowering agents. Only about 40% of patients were on any form of lipid-lowering therapy.
Capanni, M., Calella, F., Biagini, M. R., Genise, S., Raimondi, L., Bedogni, G., Svegliati-Baroni, G., Sofi, F., Milani, S., Abbate, R., Surrenti, C., and Casini, A. Prolonged n-3 polyunsaturated fatty acid supplementation ameliorates hepatic steatosis in patients with non-alcoholic fatty liver disease: a pilot study. Aliment.Pharmacol.Ther. 4-15-2006;23(8):1143-1151. View abstract.
Nakamura, N., Hamazaki, T., Ohta, M., Okuda, K., Urakaze, M., Sawazaki, S., Yamazaki, K., Satoh, A., Temaru, R., Ishikura, Y., Takata, M., Kishida, M., and Kobayashi, M. Joint effects of HMG-CoA reductase inhibitors and eicosapentaenoic acids on serum lipid profile and plasma fatty acid concentrations in patients with hyperlipidemia. Int J Clin Lab Res 1999;29(1):22-25. View abstract.
A new Cochrane systematic review, published today in the Cochrane Library, combines the results of seventy-nine randomised trials involving 112,059 people. These studies assessed effects of consuming additional omega 3 fat, compared to usual or lower omega 3, on diseases of the heart and circulation. Twenty-five studies were assessed as highly trustworthy because they were well designed and conducted.

Increased EPA levels in the blood and cell membranes effectively regulates inflammatory pathways and reduces total inflammatory ‘load’, so for any inflammatory conditions or concerns, we recommend a phase of pure EPA supplementation for at least 3-6 months. Pre-loading the body with pure EPA (without the opposing actions of DHA for uptake and utilisation) ensures constant replenishment of EPA ’supplies’ to support its high rate of turnover. Since DHA levels remain fairly stable and much lower daily amounts are required, DHA levels can be supported continually through dietary intake, or increased to 250 mg daily in later stages of treatment through supplementation.
There have been conflicting results reported about EPA and DHA and their use with regard to major coronary events and their use after myocardial infarction. EPA+DHA has been associated with a reduced risk of recurrent coronary artery events and sudden cardiac death after an acute myocardial infarction (RR, 0.47; 95% CI: 0.219–0.995) and a reduction in heart failure events (adjusted HR: 0.92; 99% CI: 0.849–0.999) (34–36). A study using EPA supplementation in combination with a statin, compared with statin therapy alone, found that, after 5 y, the patients in the EPA group (n = 262) who had a history of coronary artery disease had a 19% relative reduction in major coronary events (P = 0.011). However, in patients with no history of coronary artery disease (n = 104), major coronary events were reduced by 18%, but this finding was not significant (37). This Japanese population already has a high relative intake of fish compared with other nations, and, thus, these data suggest that supplementation has cardiovascular benefits in those who already have sufficient baseline EPA+DHA levels. Another study compared patients with impaired glucose metabolism (n = 4565) with normoglycemic patients (n = 14,080). Impaired glucose metabolism patients had a significantly higher coronary artery disease HR (1.71 in the non-EPA group and 1.63 in the EPA group). The primary endpoint was any major coronary event including sudden cardiac death, myocardial infarction, and other nonfatal events. Treatment of impaired glucose metabolism patients with EPA showed a significantly lower major coronary event HR of 0.78 compared with the non–EPA-treated impaired glucose metabolism patients (95% CI: 0.60–0.998; P = 0.048), which demonstrates that EPA significantly suppresses major coronary events (38). When looking at the use of EPA+DHA and cardiovascular events after myocardial infarction, of 4837 patients, a major cardiovascular event occurred in 671 patients (13.9%) (39). A post hoc analysis of the data from these diabetic patients showed that rates of fatal coronary heart disease and arrhythmia-related events were lower among patients in the EPA+DHA group than among the placebo group (HR for fatal coronary heart disease: 0.51; 95% CI: 0.27–0.97; HR for arrhythmia-related events: 0.51; 95% CI: 0.24–1.11, not statistically significant) (39). Another study found that there was no significant difference in sudden cardiac death or total mortality between an EPA+DHA supplementation group and a control group in those patients treated after myocardial infarction (40). Although these last 2 studies appear to be negative in their results, it is possible that the more aggressive treatment with medications in these more recent studies could attribute to this.
According to the Cardiovascular Research Institute in Maastricht in Netherlands, “Epidemiological studies show that replacing fat with carbohydrates may even be worse [than the Western-type high-fat diet] and that various polyunsaturated fatty acids (FA) have beneficial rather than detrimental effects on CVD (cardiovascular disease) outcome.” This includes fish-oil fatty acids with anti-inflammatory properties, which can help prevent and reverse a plethora of cardiovascular diseases. (19)
A new Cochrane systematic review, published today in the Cochrane Library, combines the results of seventy-nine randomised trials involving 112,059 people. These studies assessed effects of consuming additional omega 3 fat, compared to usual or lower omega 3, on diseases of the heart and circulation. Twenty-five studies were assessed as highly trustworthy because they were well designed and conducted.
In fact, dietary fat intake has been among the most widely studied dietary risk factors for breast and prostate cancers. Two studies from 2002 explain how omega-3 can protect against breast cancer. BRCA1 (breast cancer gene 1) and BRCA2 (breast cancer gene 2) are two tumor suppressor genes that, when functioning normally, help repair DNA damage, a process that also prevents tumor development.
Both omega−6 and omega−3 fatty acids are essential: humans must consume them in their diet. Omega−6 and omega−3 eighteen-carbon polyunsaturated fatty acids compete for the same metabolic enzymes, thus the omega−6:omega−3 ratio of ingested fatty acids has significant influence on the ratio and rate of production of eicosanoids, a group of hormones intimately involved in the body's inflammatory and homeostatic processes, which include the prostaglandins, leukotrienes, and thromboxanes, among others. Altering this ratio can change the body's metabolic and inflammatory state.[16] In general, grass-fed animals accumulate more omega−3 than do grain-fed animals, which accumulate relatively more omega−6.[86] Metabolites of omega−6 are more inflammatory (esp. arachidonic acid) than those of omega−3. This necessitates that omega−6 and omega−3 be consumed in a balanced proportion; healthy ratios of omega−6:omega−3, according to some authors, range from 1:1 to 1:4.[87] Other authors believe that a ratio of 4:1 (4 times as much omega−6 as omega−3) is already healthy.[88][89] Studies suggest the evolutionary human diet, rich in game animals, seafood, and other sources of omega−3, may have provided such a ratio.[90][91]
Several studies suggest that people suffering symptoms of depression and/or anxiety see improvement after adding an omega-3 supplement to their routine, even in double-blinded, randomized, controlled trials. (29, 30, 31, 32, 33) At least one study comparing a common depression medication found omega-3 supplements to be just as effective in combating depression symptoms. (34)
My initial interest in omga-3 was an article by Dr Andrew Stoll in Harvard about May 99, One of my bipolar patients had extreme OCD related to HIV which was not relevant to her. I put her on 9.6g of fish oil and continued her on her regular medication. She was well for the next 3 years with no obvious mental health problem when she was attending here.

4. Omega-3 has been found to save the lives of children going through short bowel syndrome (SBS), which is uncommon but impacts thousands of people in the United States. SBS can occur from birth (when a portion of the intestine fails to develop) or due to an infectious inflammatory disease striking premature newborns. In adults, it can be caused by surgery for Crohn's disease or injury.
“Lipid peroxidation induced by DHA enrichment modifies paracellular permeability in Caco-2 cells: protective role of taurine.” We conclude that hydrogen peroxide and peroxynitrite may be involved in the DHA-induced increase in paracellular permeability and that the protective role of taurine may be in part related to its capacity to counteract the effects of hydrogen peroxide.
A scientific review in 2014 evaluated study findings on omega-3 intake in relation to the prevention and treatment of breast cancer, the most prevalent cancer among women. The review found that EPA and DHA, as well as ALA, can differentially inhibit breast tumor development. According to this review, there is solid evidence to support the use of omega-3s as “a nutritional intervention in the treatment of breast cancer to enhance conventional therapeutics, or potentially lowering effective doses.” (16) Additionally, a 2016 study found that “very high fish consumption in early adulthood to midlife may be associated with decreased risk of breast cancer.” (17)

To evaluate the potential placebo effect, we made further subgrouping analyses. In the subgroups of studies using placebo controls, the omega-3 PUFAs still revealed a consistent positive anxiolytic association with anxiety symptoms. These phenomena meant that the anxiolytic effect of omega-3 PUFAs is probably not entirely owing to the placebo effect.
Ample evidence from animal studies supports regular supplementation with omega-3 oils as a means of lowering long-term cardiovascular risk. This may be due to omega-3 fatty acids’ effects on reducing inflammation, lowering triglycerides, reducing blood pressure, improving endothelial function, inducing new blood vessel formation after heart attack or stroke, and favorable modification of obesity-related inflammatory molecules.35-39
Jump up ^ Burch, Ernest S. (2006). Social Life in Northwest Alaska: The Structure of Iñupiaq Eskimo Nations. University of Alaska Press. p. 278. ISBN 9781889963921. Retrieved 2014-10-23. Oil was also used externally as an ointment to heal cold sores, cuts, insect bites, frostbite, rashes - in short, skin problems of all kinds. Duck or goose body-cavity fat was apparently as useful as seal or fish oil in dealing with skin problems.
Jump up ^ Burch, Ernest S. (2006). Social Life in Northwest Alaska: The Structure of Iñupiaq Eskimo Nations. University of Alaska Press. p. 278. ISBN 9781889963921. Retrieved 2014-10-23. Oil was also used externally as an ointment to heal cold sores, cuts, insect bites, frostbite, rashes - in short, skin problems of all kinds. Duck or goose body-cavity fat was apparently as useful as seal or fish oil in dealing with skin problems.
It is great for improving the condition of the dry skin by making it look shiny and vibrant. It is useful in treating various skin problems such as eczema, psoriasis, itching, skin redness, skin lesions, and rashes. In terms of psoriasis, the EPA present in fish oil restricts the growth of pro-inflammatory agents by producing arachidonic acid. Therefore, fish oil can also be applied topically to get relief from psoriasis.
Joensen, A. M., Schmidt, E. B., Dethlefsen, C., Johnsen, S. P., Tjonneland, A., Rasmussen, L. H., and Overvad, K. Dietary intake of total marine n-3 polyunsaturated fatty acids, eicosapentaenoic acid, docosahexaenoic acid and docosapentaenoic acid and the risk of acute coronary syndrome - a cohort study. Br J Nutr 2010;103(4):602-607. View abstract.
In my opinion, the key benefit of DHA lies in its unique spatial characteristics. As mentioned earlier, the extra double bond (six in DHA vs. five in EPA) and increased carbon length (22 carbons in DHA vs. 20 in EPA) means that DHA takes up takes up a lot more space than does EPA in the membrane. Although this increase in spatial volume makes DHA a poor substrate for phospholipase A2 as well as the COX and LOX enzymes, it does a great job of making membranes (especially those in the brain) a lot more fluid as the DHA sweeps out a much greater volume in the membrane than does EPA. This increase in membrane fluidity is critical for synaptic vesicles and the retina of the eye as it allows receptors to rotate more effectively thus increasing the transmission of signals from the surface of the membrane to the interior of the nerve cells. This is why DHA is a critical component of these highly fluid portions of the nerves (7). On the other hand, the myelin membrane is essentially an insulator so that relatively little DHA is found in that part of the membrane.
To date, no studies have assessed mortality or nonfatal MI in diabetic patients treated with fish oil.52–54 A recent comprehensive meta-analysis analyzed the effect of fish oil supplements on metabolic parameters when added to usual care in patients with type 2 diabetes mellitus or impaired glucose tolerance.54 The meta-analysis included a total of 23 small, randomized trials with over 1000 patients that were assessed for lipid and insulin resistance parameters. At a mean follow-up of approximately 9 weeks, triglyceride reduction was accomplished but no significant changes were seen in total cholesterol, high-density lipoprotein-cholesterol, HgA1c levels, fasting glucose levels, fasting insulin, or in body weight. The largest randomized trial to date assessed approximately 400 patients with impaired glucose tolerance or insulin-dependent diabetes mel-litus, and as reflected in the larger meta-analysis, found no effect of moderate to high doses of fish oil on diabetic parameters.55 There are insufficient randomized data to comment on the combination of fish oil and specific diabetes medications and related mortality and/or morbidity.
In your final paragraph, you suggest that a ratio of 2:1 EPA/DHA maybe best for reducing inflammation. Are you suggesting using two separate products to obtain that ratio? I can't see how it is achieveable through standard omega-3 products. Good fish oil brands are typically 60% or higher EPA, but never reach a 2:1 ratio in my product searches. According to case studies (link below), 1 gram of EPA per day (60% or more of the total omega-3 content) is sufficient and the highest efficacy.
Cancer. Research on the effects of fish oil in preventing cancer has produced conflicting results. Some population research suggests that eating fish or having higher blood levels of omega-3 fatty acids from fish oil is linked to a lower risk of different cancers, including oral cancer, pharyngeal cancer, esophageal cancer, colon cancer, rectal cancer, breast cancer, ovarian cancer, and prostate cancer. But other research suggests that eating fish does not reduce the risk of cancer.