There are three types of omega-3 fatty acids, which include EPA, DHA and ALA, which is alpha-linoleic acid. Although EPA and DHA are found to have high amounts from animal sources, ALA is found in rich concentrations in plant sources, including certain vegetable oils and flaxseeds, although fatty fish and shellfish are the best sources of EPA and DHA, according to the National Center for Complementary and Alternative Medicine. Examples of these fatty fish and shellfish include salmon, tuna, trout, crab, oysters and mussels.

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One reason omega-3 fatty acids may be so beneficial to this many aspects of health could be that they help decrease system-wide inflammation. (49, 50, 51, 52, 53) Inflammation is at the root of most diseases and is related to the development of nearly every major illness, so by eating a nutrient-dense, anti-inflammatory diet, you give your body its best chance to fight disease like it was designed to do.
In a U.K. study, children of mothers who ate more than 12 ounces a week actually scored better on tests of verbal I.Q., social behavior, and development and communication than children of mothers who ate none. In the Seychelles Islands, where people average 12 fish meals -- not ounces -- a week, there are no reports of links between mercury exposure and poor outcomes in children. These studies suggest that eating less than 12 ounces of fish each week could do more harm to a child's developing neurological system than mercury poisoning.
There was no significant association between the Hedges g and mean age (k, 17; P = .51), female proportion (k, 18; P = .32), mean omega-3 PUFA dosage (k, 19; P = .307), EPA to DHA ratio (k, 17; P = .86), dropout rate in the omega-3 PUFA group (k, 18; P = .71), duration of omega-3 PUFA treatment (k, 19; P = .14), Jadad score of randomization (k, 19; P = .10), Jadad score of blindness (k, 19; P = .57), or total Jadad score (k, 19; P = .18).
Pay attention to the quality of fish oil when purchasing it. It is obtained from almost all fishes – fresh water, farm, ocean, deep sea and shallow sea fish. All these fishes can be contaminated with toxic compounds such as mercury, arsenic, lead, forms of calcium, furans, dioxins, PCBs, and methylmercury, and can negatively affect the human body. Therefore, the fish oil used must be pure. Many companies sell ultra refined or distilled fish oil, but you should always check if the standards have been followed and research on the company or the product before adding it to your diet.
46. Gajos G, Rostoff P, Undas A, Piwowarska W. Effects of polyunsaturated omega-3 fatty acids on responsiveness to dual antiplatelet therapy in patients undergoing percutaneous coronary intervention: the OMEGA-PCI (OMEGA-3 fatty acids after pci to modify responsiveness to dual antiplatelet therapy) study. J Am Coll Cardiol. 2010;55:1671–8. [PubMed]
The National Institutes of Health (NIH) has created a website, NIH Clinical Research Trials and You, to help people learn about clinical trials, why they matter, and how to participate. The site includes questions and answers about clinical trials, guidance on how to find clinical trials through ClinicalTrials.gov and other resources, and stories about the personal experiences of clinical trial participants. Clinical trials are necessary to find better ways to prevent, diagnose, and treat diseases.

Not all forms of fish oil may be equally digestible. Of four studies that compare bioavailability of the glyceryl ester form of fish oil vs. the ethyl ester form, two have concluded the natural glyceryl ester form is better, and the other two studies did not find a significant difference. No studies have shown the ethyl ester form to be superior, although it is cheaper to manufacture.[114][115]

The results of several small studies had suggested that taking omega-3 supplements might help relieve symptoms of dry eye disease. However, a 2018 NIH-sponsored study that tested omega-3 supplements for a full year in a larger group (535 study participants) with moderate-to-severe dry eye disease found that the supplements were no more helpful than a placebo (an inactive substance).


Fish oil has only a small benefit on the risk of premature birth.[43][44] A 2015 meta-analysis of the effect of omega−3 supplementation during pregnancy did not demonstrate a decrease in the rate of preterm birth or improve outcomes in women with singleton pregnancies with no prior preterm births.[45] A systematic review and meta-analysis published the same year reached the opposite conclusion, specifically, that omega−3 fatty acids were effective in "preventing early and any preterm delivery".[46]
Respected health care organizations proposed intake recommendations for oily fish of two servings per week for healthy adults, which equates to approximately a daily total of 500 milligrams (mg) EPA and DHA.‡ The recommendation encourages adults already with or at-risk of developing cardiovascular disease to talk to their primary healthcare professional about supplementing with amounts greater than 500 mg of EPA and DHA per day. Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease.

Today the only Food and Drug Administration (FDA)-approved form of dietary omega-3 FA supplement is Lovaza (omega-3-acid ethyl esters; GlaxoSmithKline), which contains 375 mg of DHA and 465 mg of EPA per 1 g capsule. The myriad of dietary supplements of fish oil, including Kosher capsules, vary from comparable content to insignificant amounts, and for the most part can include other fats and cholesterols. In comparison, to achieve approximately 1 g of EPA and DHA in a meal, 12 ounces of canned light tuna, 2 to 3 ounces of sardines, 1.5 to 2.5 ounces of farmed Atlantic salmon, or 20 ounces of farmed catfish must be consumed (Table 1).65 Unfortunately, potentially high levels of harmful pollutants offset this source of omega-3 FA. The FDA action level for unacceptably high mercury content in fish is 1.0 μg/g. The mercury level in most fish is at or below 0.1 μg/g, but tilefish, swordfish, and king mackerel have high levels of mercury. The majority of fish species also contain <100 ng/g of polychlorinated biphenyls, which is below the FDA action level of 2000 ng/g. Dioxins, which do not have FDA action levels, are present in the majority of marine life.66

For patients without documented CAD, the American Heart Association 2006 Diet and Lifestyle Recommendations advise the consumption of at least 2 servings of fish per week, preferably fatty fish high in DHA and EPA.65 The guidelines also recommend a daily fish intake equivalent to 1 g/d of EPA and DHA for secondary prevention of CAD. Fish oil supplements containing EPA and DHA are suggested as an alternative to fatty fish consumption for secondary prevention.
There have been numerous clinical trials looking mainly at death, stroke, and cardiac outcomes related to omega 3 consumption, either in food or in supplements. Now the Cochrane Library has published the largest systematic review of these studies to date. Unfortunately, the review shows little benefit from consuming omega 3 fatty acid. This is a fairly extensive review with good statistical power:
After a large number of lab studies found that omega-3 fatty acids may be effective in slowing or reversing the growth of hormonal cancers, namely prostate and breast cancer cells, animal and human epidemiological studies have been conducted to see whether this effect occurred in real-life scenarios. The evidence is somewhat conflicting in some reports, but there is some evidence to suggest breast and prostate cancers may be potentially slowed (or the risk reduced) in people who eat a lot of oily fish and possibly those who supplement with omega-3. (66, 67, 68)

Giacco, R., Cuomo, V., Vessby, B., Uusitupa, M., Hermansen, K., Meyer, B. J., Riccardi, G., and Rivellese, A. A. Fish oil, insulin sensitivity, insulin secretion and glucose tolerance in healthy people: is there any effect of fish oil supplementation in relation to the type of background diet and habitual dietary intake of n-6 and n-3 fatty acids? Nutr.Metab Cardiovasc.Dis. 2007;17(8):572-580. View abstract.
It must be kept in mind that prostate issues have been found to be the result of the fact that men who suffer prostate issues are found in males who’s testosterone levels dropped to dangerous levels. If one bothers to research this fact it will be found that studies show that testosterone controls estrogen levels and as such estrogen levels get out of control and begin to create problems the likes of which our society is suffering right now.
Ramakrishnan, U., Stein, A. D., Parra-Cabrera, S., Wang, M., Imhoff-Kunsch, B., Juarez-Marquez, S., Rivera, J., and Martorell, R. Effects of docosahexaenoic acid supplementation during pregnancy on gestational age and size at birth: randomized, double-blind, placebo-controlled trial in Mexico. Food Nutr Bull 2010;31(2 Suppl):S108-S116. View abstract.
Gajos G1, Rostoff P, Undas A, et al. Effects of polyunsaturated omega-3 fatty acids on responsiveness to dual antiplatelet therapy in patients undergoing percutaneous coronary intervention: the OMEGA-PCI (OMEGA-3 fatty acids after pci to modify responsiveness to dual antiplatelet therapy) study. J Am Coll Cardiol. 2010 Apr 20;55(16):1671-8. View abstract.
Jump up ^ Miller M, Stone NJ, Ballantyne C, Bittner V, Criqui MH, Ginsberg HN, Goldberg AC, Howard WJ, Jacobson MS, Kris-Etherton PM, Lennie TA, Levi M, Mazzone T, Pennathur S (May 2011). "Triglycerides and cardiovascular disease: a scientific statement from the American Heart Association". Circulation. 123 (20): 2292–333. doi:10.1161/CIR.0b013e3182160726. PMID 21502576.
56. Davidson MH, Stein EA, Bays HE, et al. COMBination of prescription Omega-3 with Simvastatin (COMBOS) Investigators. Efficacy and tolerability of adding prescription omega-3 fatty acids 4 g/d to simvastatin 40 mg/d in hypertriglyceridemic patients: an 8-week, randomized, double-blind, placebo-controlled study. Clin Ther. 2007;29:1354–1367. [PubMed]
The 'essential' fatty acids were given their name when researchers found that they are essential to normal growth in young children and animals. The omega−3 fatty acid DHA, also known as docosahexaenoic acid, is found in high abundance in the human brain.[70] It is produced by a desaturation process, but humans lack the desaturase enzyme, which acts to insert double bonds at the ω6 and ω3 position.[70] Therefore, the ω6 and ω3 polyunsaturated fatty acids cannot be synthesized and are appropriately called essential fatty acids.[70]
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.
The reason why fish oil could increase a man’s risk of prostate cancer is IMBALANCE. Like I said earlier, omega-6 fatty acids aren’t bad for you. In fact, if your diet contains too many omega-3 fatty acids, your immune system wouldn’t work very well because omega-3 and omega-6 fatty acids are meant to work in a system of checks and balances. Omega-3 fatty acids suppress inflammation, and omega-6 fatty acids promote inflammation, which actually supports your body’s natural system of defense like activating your white blood cells.
Badia-Tahull, M. B., Llop-Talaveron, J. M., Leiva-Badosa, E., Biondo, S., Farran-Teixido, L., Ramon-Torrell, J. M., and Jodar-Masanes, R. A randomised study on the clinical progress of high-risk elective major gastrointestinal surgery patients treated with olive oil-based parenteral nutrition with or without a fish oil supplement. Br.J.Nutr. 2010;104(5):737-741. View abstract.
Widenhorn-Müller  K, Schwanda  S, Scholz  E, Spitzer  M, Bode  H.  Effect of supplementation with long-chain ω-3 polyunsaturated fatty acids on behavior and cognition in children with attention deficit/hyperactivity disorder (ADHD): a randomized placebo-controlled intervention trial.  Prostaglandins Leukot Essent Fatty Acids. 2014;91(1-2):49-60. doi:10.1016/j.plefa.2014.04.004PubMedGoogle ScholarCrossref

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.


First, all Omega-3 products are not alike. Here's what I learned about Omega-3 from my research. The "3" relates to three sources of Omega-3 fatty acids. Two of them, DHA and EPA are found in marine products such as fish and krill. The third source, ALA, is from plants. So with fish oil you are getting two of the three sources at once. That makes sense to me as a good reason to take Omega-3 fish oil. You will also note below that many of the reasons we choose to take Omega-3 do not occur with plant-based products.
My estimate is that close to 90 percent of fish oils on the market today may contain mercury and pesticide residues plus hydrogenated oils. Of course, this is my opinion based on my own research from visiting different manufacturing plants, interviewing companies, and studying the research and the listed ingredients of typical fish oils. I would stay away from ALL fish oils that do not have antioxidants like astaxanthin, which help stabilize the oil from going rancid. I always look for astaxanthin as part of any high-quality fish oil supplement.

An 18-month study was published in 2014 that evaluated how borage seed oil — rich in GLA — and fish oil rich fared against each other in treating patients with rheumatoid arthritis. It was discovered that all three groups (one taking fish oil, one taking borage oil and one taking a combination of the two) “exhibited significant reductions” in disease activity, and no therapy outperformed the others. For all three, “meaningful clinical responses” were the same after nine months. (11)
Peroxides can be produced when fish oil spoils. A study commissioned by the government of Norway concluded there would be some health concern related to the regular consumption of oxidized (rancid) fish/marine oils, particularly in regards to the gastrointestinal tract, but there is not enough data to determine the risk. The amount of spoilage and contamination in a supplement depends on the raw materials and processes of extraction, refining, concentration, encapsulation, storage and transportation.[51] ConsumerLab.com reports in its review that it found spoilage in test reports it ordered on some fish oil supplement products.[52]
This under-the-radar grain is a nutritional powerhouse — and one of the most potent sources of the omega-3 alpha-Linolenic acid (ALA). Sprinkle flaxseeds over your morning oatmeal for a pleasant nutty flavor, or blend them into fruit smoothies to satisfy a picky palate. Need more ideas? Check out The Flaxseed Recipe Book, an easy-to-follow guide for adding flaxseeds to your favorite soups, salads, and main courses.
Recent studies have shown that the consumption of fish oil (or, more specifically, the omega-3 fatty acids found in fish oil) can improve fertility in both men and women. DHA, which is a byproduct of omega-3 fatty acids, plays a key role in the mobility of sperm and health of sperm in men. Low blood levels of DHA have been linked to decreased fertility. Animal studies have found that the DHA in fish is vital to changing dysfunctional round-headed sperm into strong swimmers with cone-shaped heads packed with egg-opening proteins. (29)
It’s uncertain whether omega-3 fatty acid supplements are helpful for depression. Although some studies have had promising results, a 2015 evaluation of 26 studies that included more than 1,400 people concluded that if there is an effect, it may be too small to be meaningful. Other analyses have suggested that if omega-3s do have an effect, EPA may be more beneficial than DHA and that omega-3s may best be used in addition to antidepressant medication rather than in place of it. 
For rheumatoid arthritis, one systematic review found consistent, but modest, evidence for the effect of marine n−3 PUFAs on symptoms such as "joint swelling and pain, duration of morning stiffness, global assessments of pain and disease activity" as well as the use of non-steroidal anti-inflammatory drugs.[35] The American College of Rheumatology has stated that there may be modest benefit from the use of fish oils, but that it may take months for effects to be seen, and cautions for possible gastrointestinal side effects and the possibility of the supplements containing mercury or vitamin A at toxic levels. The National Center for Complementary and Integrative Health has concluded that "[n]o dietary supplement has shown clear benefits for rheumatoid arthritis", but that there is preliminary evidence that fish oil may be beneficial, but needs further study.[36]
Wohl, D. A., Tien, H. C., Busby, M., Cunningham, C., Macintosh, B., Napravnik, S., Danan, E., Donovan, K., Hossenipour, M., and Simpson, R. J., Jr. Randomized study of the safety and efficacy of fish oil (omega-3 fatty acid) supplementation with dietary and exercise counseling for the treatment of antiretroviral therapy-associated hypertriglyceridemia. Clin.Infect.Dis. 11-15-2005;41(10):1498-1504. View abstract.
Several large trials have evaluated the effect of fish or fish oils on heart disease. In the Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardio (known as the GISSI Prevention Trial), heart attack survivors who took a 1-gram capsule of omega-3 fats every day for three years were less likely to have a repeat heart attack, stroke, or die of sudden death than those who took a placebo. (2) Notably, the risk of sudden cardiac death was reduced by about 50 percent. In the more recent Japan EPA Lipid Intervention Study (JELIS), participants who took EPA plus a cholesterol-lowering statin were less likely to have a major coronary event (sudden cardiac death, fatal or nonfatal heart attack, unstable angina, or a procedure to open or bypass a narrowed or blocked coronary artery) than those who took a statin alone. (3)
ACS Breast Cancer Screening Guideline CDC Guideline for Prescribing Opioids CDC Guideline for Prevention of Surgical Site Infections Consensus Definitions for Sepsis and Septic Shock Global Burden of Cancer, 1990-2016 Global Burden of Disease in Children, 1990-2013 Global Burden of Hypertension, 1990-2015 Global Firearm Mortality, 1990-2016 Health Care Spending in the US and Other High-Income Countries Income and Life Expectancy in the US JNC 8 Guideline for Management of High Blood Pressure President Obama on US Health Care Reform Screening for Colorectal Cancer Screening for Depression in Adults Screening for Prostate Cancer Statins for Primary Prevention of Cardiovascular Disease The State of US Health, 1990-2016 US Burden of Cardiovascular Disease, 1990-2016 WMA Declaration of Helsinki, 7th Revision

Only fish and breast milk contain all the members of the omega-3 family, including its two main stars, EPA and DHA. Because Americans as a rule consume far too few omega-3s from fish or fish oil, it’s no surprise that the majority of Americans have low omega-3 index levels as well. A recent study of global omega-3 index levels found that an estimated 95% of Americans (with the exception of folks from Alaska) had an omega-3 index of 4 or below, putting them in the high risk category (5, 6, 7).

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.
Belalcazar, L. M., Reboussin, D. M., Haffner, S. M., Reeves, R. S., Schwenke, D. C., Hoogeveen, R. C., Pi-Sunyer, F. X., and Ballantyne, C. M. Marine omega-3 fatty acid intake: associations with cardiometabolic risk and response to weight loss intervention in the Look AHEAD (Action for Health in Diabetes) study. Diabetes Care 2010;33(1):197-199. View abstract.
Fish oil is a commonly used dietary supplement, with sales in the U.S. alone reaching $976 million in 2009.[48] Problems of quality have been identified in periodic tests by independent researchers of marketed supplements containing fish oil and other marine oils. These problems include contamination, inaccurate listing of EPA and DHA levels, spoilage and formulation issues.[49]
It is well known that fish oil has the ability to improve vision. It also helps in avoiding age-related macular degeneration. The National Eye Institute at the National Institute of Health in the United States plans to conduct a nationwide study to evaluate the effect of fish oil in treating macular degeneration. This study will provide strong scientific evidence regarding the benefits of fish oil for eye care, thereby allowing government agencies and physicians to strongly recommend fish oil for macular degeneration.
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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