ALA is an essential fatty acid, which means that you need it but you must get this fat from your diet because your body is unable to produce it. In general, omega 3 fats are a crucial component of all cell membranes, including the eye (retina) and brain as well as aiding in the process of energy production to support functions involving the heart, lungs, immune system, and hormones (endocrine system), work properly.1
The most widely available dietary source of EPA and DHA is cold-water oily fish, such as salmon, herring, mackerel, anchovies, and sardines. Oils from these fish have a profile of around seven times as much omega-3 oils as omega-6 oils. Other oily fish, such as tuna, also contain omega-3 in somewhat lesser amounts. Although fish is a dietary source of omega-3 oils, fish do not synthesize them; they obtain them from the algae (microalgae in particular) or plankton in their diets.[22]

Heavy metal poisoning by the body's accumulation of traces of heavy metals, in particular mercury, lead, nickel, arsenic, and cadmium, is a possible risk from consuming fish oil supplements.[medical citation needed] Also, other contaminants (PCBs, furans, dioxins, and PBDEs) might be found, especially in less-refined fish oil supplements.[citation needed] However, heavy metal toxicity from consuming fish oil supplements is highly unlikely, because heavy metals selectively bind with protein in the fish flesh rather than accumulate in the oil. An independent test in 2005 of 44 fish oils on the US market found all of the products passed safety standards for potential contaminants.[107][unreliable source?]
ALA is an essential fatty acid, meaning that your body can’t make it, so you must get it from the foods and beverages you consume. Your body can convert some ALA into EPA and then to DHA, but only in very small amounts. Therefore, getting EPA and DHA from foods (and dietary supplements if you take them) is the only practical way to increase levels of these omega-3 fatty acids in your body.
Throughout their history, the Council for Responsible Nutrition and the World Health Organization have published acceptability standards regarding contaminants in fish oil. The most stringent current standard is the International Fish Oils Standard.[108][non-primary source needed] Fish oils that are molecularly distilled under vacuum typically make this highest-grade; levels of contaminants are stated in parts per billion per trillion.[citation needed][109]
It helps maintain a good luster of the hair because omega-3 has growth stimulating properties since it provides nourishment to the follicles. It aids in the development of hair and in preventing hair loss. A good supply of protein is also necessary for hair growth, and since most fish varieties are rich in protein, eating fish helps to keep hair healthy.

The effect of fish oil on incident atrial fibrillation has not been studied in large randomized trials, and observational population-based trials show mixed results. The Danish Diet, Cancer and Health Study, and the Rotterdam Study followed 47,000 and 5100 middle-aged adults, respectively.45,46 Neither study found that the consumption of fish oil affected the incidence of atrial fibrillation. Similar findings were seen in the Women’s Health Initiative where there was no association between fish and omega-3 FA intake regarding incident atrial fibrillation.47 However, in a 12-year prospective, observational study of 4815 adults over the age of 65, daily fish consumption was associated with a 31% risk reduction in incident atrial fibrillation.48

After the age of five, the development of the brain and CNS starts to reduce and the body’s need for DHA reduces. This is a good time to increase EPA in the diet, as studies show that EPA can help with childhood behaviour and academic performance, as well as focus, attention and reducing aggression. Dry skin conditions, asthma and allergies are also common in children and good levels of EPA at this time can help reduce the inflammation associated with these issues.

Dr. Holub has provided the questions and answers for several emails he has received over the years regarding omega-3 fatty acids for health.  If you have a question regarding omega-3, it is likely that Dr. Holub has answered it either here in this section, or elsewhere on the site (e.g. check the scientific overview section for general questions regarding omega-3).  To quickly find your answer, please use our search bar located in the top right section of this page.  After searching our site, and  you still cannot find the answer to your question, we invite you to ask Dr. Holub a question here.

Fish oils seem to decrease blood pressure. Taking fish oils along with medications for high blood pressure might cause your blood pressure to go too low.Some medications for high blood pressure include captopril (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), diltiazem (Cardizem), Amlodipine (Norvasc), hydrochlorothiazide (HydroDiuril), furosemide (Lasix), and many others.
The hypotriglyceridemic effect of fish oil is well established and is related to both dose and baseline triglyceride level. Patients with triglycerides <90 mg/dL will be negligibly affected unless very high doses of omega-3 FA are used.67,68 However, in patients with triglycerides >200 mg/dL, who are treated with 4 g/d of fish oil, a 30% reduction in triglycerides is expected.17,69 For patients with triglycerides >500 mg/dL who are at risk for pancreatitis, the National Cholesterol Education Program Adult Treatment Panel III guidelines recommend using fish oil supplements as an adjunctive therapy to fibrates and nicotinic acid.70 Lovaza capsules have been shown to be effective, safe, and comparable to gemfibrozil in treating triglycerides at this range.71,72 The official label recommendation for Lovaza is for patients with triglycerides >500 mg/dL.73
Some studies suggest that people who get higher amounts of omega-3s from foods and dietary supplements may have a lower risk of breast cancer and perhaps colorectal cancer. More research is needed to confirm this possible link. Whether omega-3s affect the risk of other cancers is not clear. Clinical trials to examine this possibility are in progress.
According to the 2012 National Health Interview Survey, which included a comprehensive survey on the use of complementary health approaches in the United States, fish oil supplements are the nonvitamin/nonmineral natural product most commonly taken by both adults and children. The survey findings indicated that about 7.8 percent of adults (18.8 million) and 1.1 percent of children age 4 to 17 (664,000) had taken a fish oil supplement in the previous 30 days.
What Seafood Can You Eat When Pregnant? How Often Can You Eat Canned Salmon? Should You Eat Walnuts or Almonds for Omega-3? How to Bake Walleye Filets What Is the Cholesterol Content of Fish & Shellfish? Gout Diet With Fish Octopus and Omega 3s Fish and Shellfish With High Levels of Omega-3 Fatty Acids How to Cook Croaker Fish Which Fish Contains the Least Amount of Mercury? What Kind of Cold Water Fish Are Healthy to Eat? How to Cook Scrambled Eggs With Sardines What Foods Contain Vitamin F? Can I Eat Salmon While Pregnant? How Much Salmon per Week Due to Mercury? How to Cook Basa Fillet How to Bake or Broil Tilapia Vitamin B12 & Fish Oil Fish with the Highest Protein Content How to Broil Cod Fillets
Evidence linking fish oil and cancer has been all over the map. Some research suggests diets high in fatty fish or fish oil supplements might reduce the risk of certain cancers, including prostate cancer. Other research shows just the opposite, a  link between eating a lot of oily fish or taking potent fish oil supplements and a 43% increased risk for prostate cancer overall, and a 71% increased risk for aggressive prostate cancer.
Disclaimer: The entire contents of this website are based upon the opinions of Dr. Mercola, unless otherwise noted. Individual articles are based upon the opinions of the respective author, who retains copyright as marked. The information on this website is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. It is intended as a sharing of knowledge and information from the research and experience of Dr. Mercola and his community. Dr. Mercola encourages you to make your own health care decisions based upon your research and in partnership with a qualified health care professional. If you are pregnant, nursing, taking medication, or have a medical condition, consult your health care professional before using products based on this content.

Dioxins and PCBs may be carcinogenic at low levels of exposure over time. These substances are identified and measured in one of two categories, dioxin-like PCBs and total PCBs. While the U.S. FDA has not set a limit for PCBs in supplements, the Global Organization for EPA and DHA (GOED) has established a guideline allowing for no more than 3 picograms of dioxin-like PCBs per gram of fish oil. In 2012, samples from 35 fish oil supplements were tested for PCBs. Trace amounts of PCBs were found in all samples, and two samples exceeded the GOED‘s limit.[52] Although trace amounts of PCBs contribute to overall PCB exposure, Consumerlab.com claims the amounts reported by tests it ordered on fish oil supplements are far below those found in a single typical serving of fish.[52]


Fearon, K. C., Von Meyenfeldt, M. F., Moses, A. G., Van Geenen, R., Roy, A., Gouma, D. J., Giacosa, A., Van Gossum, A., Bauer, J., Barber, M. D., Aaronson, N. K., Voss, A. C., and Tisdale, M. J. Effect of a protein and energy dense n-3 fatty acid enriched oral supplement on loss of weight and lean tissue in cancer cachexia: a randomised double blind trial. Gut 2003;52(10):1479-1486. View abstract.

In total, 19 articles with 19 data sets revealed the main results of the meta-analysis, namely that there was a significantly better association of treatment with reduced anxiety symptoms in patients receiving omega-3 PUFA treatment than in those not receiving it (k, 19; Hedges g, 0.374; 95% CI, 0.081-0.666; P = .01; Figure 2), with significant heterogeneity (Cochran Q, 178.820; df, 18; I2, 89.934%; P < .001) but no significant publication bias via Egger regression (t, 1.736; df, 17; P = .10) or inspection of the funnel plot (eFigure 2 in the Supplement). According to the trim-and-fill test, there was no need for adjustment for publication bias. The meta-analysis results remained significant after removal of any one of the included studies, which indicated that the significant results are not owing to any single study.
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.

×