Fatty predatory fish like sharks, swordfish, tilefish, and albacore tuna may be high in omega-3 fatty acids, but due to their position at the top of the food chain, these species may also accumulate toxic substances through biomagnification. For this reason, the United States Environmental Protection Agency recommends limiting consumption (especially for women of childbearing age) of certain (predatory) fish species (e.g. albacore tuna, shark, king mackerel, tilefish and swordfish) due to high levels of the toxic contaminant mercury. Dioxin, PCBs and chlordane are also present.[13] Fish oil is used as a component in aquaculture feed. More than 50 percent of the world's fish oil used in aquaculture feed is fed to farmed salmon.[14]

Although there was significant heterogeneity among the included studies (Cochran Q, 178.820; df, 18; I2, 89.934%; P < .001), the sensitivity test suggested that the main significant results of the meta-analysis would not change after removal of any of the included studies. However, through direct inspection of the forest plot, we detected the potential influence of some outliers, such as the studies by Sohrabi et al56 and Yehuda et al.61 These 2 studies evaluated anxiety symptoms with a visual analog scale of anxiety and test anxiety severity, which are seldom used in psychiatric research and lack a definite report to prove their equivalent sensitivity and specificity to some other frequently used anxiety rating scales, such as depression, anxiety, and stress scales or the Hamilton anxiety rating scale. Therefore, these studies might have affected the interpretation of the current meta-analysis.

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.


Studies don’t seem to mention blood content of omega 6, or saturated fats–the overall balnce of triglycerides, so they seem to have been done in a “vacuum”. At least, the data is so presented. Also, high protein may be an issue not being tested, but hovering in the background of the participants’ diets. Many “miracle cures”, and I wish it wasnt so, are being not only “debunked”, but “proven” outright dangerous.
Excessive amounts of chemicals. Using excessive amounts of fish products such as shark, farm raised salmon or mackerel can be dangerous. These products may be exposed to excessive amounts of chemicals such as mercury which can build up in the body and cause negative effects. While it is healthy to consume fish, it is important to seek out quality sources to avoid exposure to these chemicals. Using a supplement to get high levels of omega-3s into your system is also recommended because these products are produced in such a way that they will not expose you to unsafe chemicals.

Marine and freshwater fish oil vary in contents of arachidonic acid, EPA and DHA.[15] The various species range from lean to fatty and their oil content in the tissues has been shown to vary from 0.7% to 15.5%.[16] They also differ in their effects on organ lipids.[15] Studies have revealed that there is no relation between total fish intake or estimated omega−3 fatty acid intake from all fish, and serum omega−3 fatty acid concentrations.[17] Only fatty fish intake, particularly salmonid, and estimated EPA + DHA intake from fatty fish has been observed to be significantly associated with increase in serum EPA + DHA.[17]


It’s no surprise that fish — particularly cold-water fatty fish like salmon, mackerel, and anchovies — are rich in omega-3s. It’s called fish oil for a reason, right? Mackerel, for instance, may have more than 3300 mg of omega-3 per serving — that’s more than 6 times the recommended per day dose for healthy adults. Not a huge fish connoisseur? Try some of the quick, simple recipes in Cooking with Fish Like a Pro, an accessible collection of fish recipes to suit every palate.
Fish oil therapy is efficacious and safe for patients with severe to moderate hypertriglyceridemia. Combination therapy with HMG-CoA reductase inhibitors is also efficacious and has not been associated with any serious adverse reactions. Fish oil therapy added to fenofibrate in patients with severe hypertriglyceridemia is also effective and safe. Accordingly, it may be a safe and effective adjunct in the pharmacotherapy of the mixed lipid disorder that is frequently encountered in patients with the metabolic syndrome and/or type II diabetes mellitus.
Omega 3 fatty acids—found in supplements and naturally in some foods like certain fish, and nuts and seeds—have long been touted for their health benefits, especially heart health. Yet, a lot is still unknown, including whether it's better to get your omega 3 fats from pills or in food—and the debate continues regarding how much they may actually help you avoid heart disease.
We’ve already seen that fish oil can help with depression-like symptoms in rats, but what about people? A study published in the journal Nutritional Neuroscience evaluated the effects of fish oil supplementation on prefrontal metabolite concentrations in adolescents with major depressive disorder. Researchers found that there was a 40 percent decrease in major depression disorder symptoms in addition to marked improvements in amino acid and nutrition content in the brain, specifically, the right dorsolateral prefrontal cortex. (21)
If you get your omega-3 index measured, you’ll know if your current efforts are sufficient. And this knowledge is especially important given that even health-conscious people are not always self-aware. One survey found that in a group of people with omega-3 index levels in the intermediate risk range, some 30% believed they were consuming enough omega-3s (11). One registered dietitian wrote a compelling story about exactly this experience. She discovered she was in the intermediate range, in spite of her intentions to eat enough fish.
Reduce Metabolic Syndrome Symptoms: The cluster of risk factors known as metabolic syndrome includes abdominal obesity, high blood sugar, high triglycerides, high blood pressure and low HDL cholesterol. These risk factors are indicative of a high chance you might develop heart disease, stroke or diabetes. Multiple studies have found omega-3 supplementation improve the symptoms of metabolic syndrome and may help to protect you from the related diseases. (22, 23, 24, 25)
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.
Funding/Support: The work was supported in part by grant 17H04253, Grant-in-Aid for Scientific Research (B) from the Japan Society for the Promotion of Science; grant 30-A-17 from the National Cancer Center Research and Development Fund; grants MOST106-2314-B-039-027-MY, 106-2314-B-038-049, 106-2314-B-039-031, 106-2314-B-039-035, 104-2314-B-039-022-MY2, and 104-2314-B-039-050-MY3 from the Ministry of Science and Technology, Taiwan; grant HRI-EX105-10528NI from the National Health Research Institutes, Taiwan; and grants CRS-106-063, DMR-107-202, and DMR-107-204 from the China Medical University, Taiwan.
Jump up ^ Abdelhamid, Asmaa S; Brown, Tracey J; Brainard, Julii S; Biswas, Priti; Thorpe, Gabrielle C; Moore, Helen J; Deane, Katherine HO; AlAbdulghafoor, Fai K; Summerbell, Carolyn D; Worthington, Helen V; Song, Fujian; Hooper, Lee (18 July 2018). "Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease". Cochrane Database of Systematic Reviews. doi:10.1002/14651858.CD003177.pub3.
The evidence linking the consumption of marine omega−3 fats to a lower risk of cancer is poor.[8][13] With the possible exception of breast cancer,[8][14][15] there is insufficient evidence that supplementation with omega−3 fatty acids has an effect on different cancers.[5][16] The effect of consumption on prostate cancer is not conclusive.[8][15] There is a decreased risk with higher blood levels of DPA, but an increased risk of more aggressive prostate cancer was shown with higher blood levels of combined EPA and DHA.[17] In people with advanced cancer and cachexia, omega−3 fatty acids supplements may be of benefit, improving appetite, weight, and quality of life.[18]
Walnuts are chock full of healthy fats — including omega-3s — and also contain a slew of other nutrients like magnesium, biotin, and vitamin E. Some studies even suggest that eating walnuts improves memory, learning ability, and motor development.1 Walnuts are versatile, too — try them with fresh or dried fruit, in salads, or baked into desserts. Get started with these banana walnut waffles — made with coconut sugar and unsweetened almond milk.

There is also evidence that mothers who use EPA and DHA supplementation during pregnancy and breastfeeding may protect their children against allergies. This may be due to the fact that fish-oil supplementation has been associated with decreased levels of body cells associated with inflammation and immune response (26). In a study about food allergy and IgE-associated eczema, the period prevalence of food allergy was lower in the maternal EPA+DHA supplementation group compared to placebo (P < 0.05), and the incidence of IgE-associated eczema was also lower in the maternal EPA+DHA supplementation group compared to placebo (P < 0.05) (27).


Aceite de Pescado, Acides Gras Oméga-3, Acides Gras Oméga 3, Acides Gras Oméga 3 Sous Forme Ester Éthylique, Acides Gras N-3, Acides Gras Polyinsaturés N-3, Acides Gras W3, ACPI, EPA/DHA Ethyl Ester, Ester Éthylique de l'AEP/ADH, Fish Body Oil, Herring Oil, Huile de Foie de Morue, Huile de Hareng, Huile de Menhaden, Huile de Poisson, Huile de Saumon, Huile de Thon, Huile Lipidique Marine, Huile Marine, Huiles Marines, Lipides Marins, Marine Lipid Concentrate, Marine Fish Oil, Marine Lipid Oil, Marine Lipids, Marine Oil, Marine Oils, Marine Triglyceride, Menhaden Oil, N-3 Fatty Acids, N3-polyunsaturated Fatty Acids, Omega 3, Oméga 3, Omega-3, Oméga-3, Omega-3 Fatty Acid Ethyl Ester, Omega-3 Fatty Acids, Omega 3 Fatty Acids, Omega-3 Marine Triglycerides, PUFA, Salmon Oil, Triglycérides Marins, Tuna Fish Oil, Tuna Oil, W-3 Fatty Acids.
Human diet has changed rapidly in recent centuries resulting in a reported increased diet of omega−6 in comparison to omega−3.[83] The rapid evolution of human diet away from a 1:1 omega−3 and omega−6 ratio, such as during the Neolithic Agricultural Revolution, has presumably been too fast for humans to have adapted to biological profiles adept at balancing omega−3 and omega−6 ratios of 1:1.[84] This is commonly believed to be the reason why modern diets are correlated with many inflammatory disorders.[83] While omega−3 polyunsaturated fatty acids may be beneficial in preventing heart disease in humans, the level of omega−6 polyunsaturated fatty acids (and, therefore, the ratio) does not matter.[78][85]

Thank you for your kind comment. As pointed out above, the main limitation of our meta-analysis is the heterogeneity, which we address several times in our main manuscript. We included studies with several different situations and participants with different underlying diseases, which would also result in wide heterogeneity in our meta-analysis. Based upon our post-hoc analysis, there was some common characteristics among the six trials with nominally significant results, including specific clinical diagnoses (5/6) and, placebo-control (4/6), which had also previously been addressed in our subgroup meta-analysis. Therefore, we suggested future placebo-controlled trials investigating the treatment effect of omega-3 in participants with specific clinical diagnoses should be warranted. In addition, improving underlying specific clinical diagnoses (5/6), good quality (placebo-control (4/6), low drop-out rate (zero in Exp/control groups: 4/6)), and long treatment duration (>= 12 weeks: 4/6) are all good indicators of high quality.
Anxiety, the most commonly experienced psychiatric symptom, is a psychological state derived from inappropriate or exaggerated fear leading to distress or impairment. The lifetime prevalence of any anxiety disorder is reported to be approximately 1 in 3.1 Anxiety is often comorbid with depressive disorders2 and is associated with lower health-related quality of life3 and increased risk of all-cause mortality.4 Treatment options include psychological treatments, such as cognitive-behavioral therapy and pharmacological treatments, mainly with selective serotonin reuptake inhibitors.5 Individuals with anxiety and related disorders tend to be more concerned about the potential adverse effects of pharmacological treatments (eg, sedation or drug dependence) and may be reluctant to engage in psychological treatments that can be time-consuming and costly, as well as sometimes limited in availability.6 Thus, evidence-based and safer treatments are required, especially for anxious patients with comorbid medical conditions.

The American Heart Association (AHA) recommends that everyone eats fish (particularly fatty, coldwater fish) at least twice a week. Salmon, mackerel, herring, sardines, lake trout, and tuna are especially high in omega-3 fatty acids. While foods are your best bet for getting omega-3s in your diet, fish oil supplements are also available for those who do not like fish. The heart-healthy benefits of regular doses of fish oil supplements are unclear, so talk to your doctor to see if they're right for you. If you have heart disease or high triglyceride levels, you may need even more omega-3 fatty acids. Ask your doctor if you should take higher doses of fish oil supplements to get the omega-3s you need.


Krauss-Etschmann, S., Hartl, D., Rzehak, P., Heinrich, J., Shadid, R., Del, Carmen Ramirez-Tortosa, Campoy, C., Pardillo, S., Schendel, D. J., Decsi, T., Demmelmair, H., and Koletzko, B. V. Decreased cord blood IL-4, IL-13, and CCR4 and increased TGF-beta levels after fish oil supplementation of pregnant women. J.Allergy Clin.Immunol. 2008;121(2):464-470. View abstract.
Marine and freshwater fish oil vary in contents of arachidonic acid, EPA and DHA.[15] The various species range from lean to fatty and their oil content in the tissues has been shown to vary from 0.7% to 15.5%.[16] They also differ in their effects on organ lipids.[15] Studies have revealed that there is no relation between total fish intake or estimated omega−3 fatty acid intake from all fish, and serum omega−3 fatty acid concentrations.[17] Only fatty fish intake, particularly salmonid, and estimated EPA + DHA intake from fatty fish has been observed to be significantly associated with increase in serum EPA + DHA.[17]
High blood pressure. Fish oil seems to slightly lower blood pressure in people with moderate to very high blood pressure. Some types of fish oil might also reduce blood pressure in people with slightly high blood pressure, but results are inconsistent. Fish oil seems to add to the effects of some, but not all, blood pressure-lowering medications. However, it doesn't seem to reduce blood pressure in people with uncontrolled blood pressure who are already taking blood pressure-lowering medications.
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