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.
A 2009 metastudy found that patients taking omega-3 supplements with a higher EPA:DHA ratio experienced fewer depressive symptoms. The studies provided evidence that EPA may be more efficacious than DHA in treating depression. However, this metastudy concluded that due to the identified limitations of the included studies, larger, randomized trials are needed to confirm these findings.[40]

A tremendous body of research has been conducted on these important nutrients since it was first discovered in the 1950s that fish oil offered many health benefits and that these benefits were attributable to a type of polyunsaturated fat called omega-3. Despite the volumes of research on omega-3s, it is only in recent years (within the last 15 years or so) that the actions of EPA and DHA have come to be understood individually. Researchers now often investigate the actions of EPA and DHA individually rather than together, no longer simply under the generic label omega-3 as they are widely referred to.


Maximizing the benefits you get from omega-3s is highly dependent on how they are absorbed and transported throughout your body. Although these fatty acids are water soluble, they cannot be easily transported into your blood in their free form. Therefore, they need to be packaged in lipoprotein vehicles for them to be better absorbed into your bloodstream.


Fish oil is very beneficial for pregnant women because the DHA present in it helps in the development of the eyes and brain of the baby. It also helps to avoid premature births, low birth weight, and miscarriages. Research conducted in Denmark, which involved 8,729 pregnant women, concluded that a diet with low amounts of fish resulted in a higher risk of premature or preterm babies.
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.
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.
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.
Haberka, M., Mizia-Stec, K., Mizia, M., Janowska, J., Gieszczyk, K., Chmiel, A., Zahorska-Markiewicz, B., and Gasior, Z. N-3 polyunsaturated fatty acids early supplementation improves ultrasound indices of endothelial function, but not through NO inhibitors in patients with acute myocardial infarction: N-3 PUFA supplementation in acute myocardial infarction. Clin.Nutr. 2011;30(1):79-85. View abstract.
The health benefits of fish oil include its ability to aid in weight loss and healthy pregnancy. It also promotes fertility and skin care (particularly for psoriasis and acne). It is beneficial in the treatment of various heart diseases, high cholesterol, depression, anxiety, ADHD, weak immune system, cancer, diabetes, inflammation, arthritis, IBD, AIDS, Alzheimer’s disease, eye disorders, macular degeneration, and ulcers.
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
The bottom line of all that is that there was no clear health benefit from consuming omega-3 fatty acids in food or supplements. There was a suggestion of a possible benefit from LCn3 on cardiac events, but this did not hold up when they took into consideration the quality of the evidence. The better trials, with less risk of bias, tended to be negative.
Most U.S. adults fail to consume adequate amounts of foods rich in EPA and DHA on a regular basis (at least 8 ounces of fatty fish per week is recommended), and probably consume too many omega-6 fats in comparison (soybean oil, canola oil, cottonseed oil, etc.). This omega-3:omega-6 imbalance can have a negative effect on inflammation patterns and may also be implicated as a contributing factor to other processes related to cellular metabolism, hormone signaling, and even weight regulation.

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.


A Cochrane meta-analysis published in June 2012 found no significant protective effect for cognitive decline for those aged 60 and over and who started taking fatty acids after this age. A co-author of the study said to Time, "Our analysis suggests that there is currently no evidence that omega-3 fatty acid supplements provide a benefit for memory or concentration in later life".[43]

Krill oil is a source of omega−3 fatty acids.[116] The effect of krill oil, at a lower dose of EPA + DHA (62.8%), was demonstrated to be similar to that of fish oil on blood lipid levels and markers of inflammation in healthy humans.[117] While not an endangered species, krill are a mainstay of the diets of many ocean-based species including whales, causing environmental and scientific concerns about their sustainability.[118][119][120]

Alpha-linolenic Acid (ALA): This plant-based omega-3 is found in green, leafy vegetables, flaxseeds, chia seeds and canola, walnut and soybean oils (although those rancid oils are not ones I generally recommend). ALA is known as a short-chain omega-3, meaning your body has to convert it into longer-chained EPA and DHA to synthesize it. This process is rather inefficient and only about one percent of the ALA you consume is converted to the long-chain version your body needs (although this percentage is slightly higher for women).

Fish oil is useful in the treatment of arthritis, rheumatism, Raynaud’s symptoms and similar conditions. Using the fish oil can help in reducing the need for large dosages of NSAIDs (non-steroidal anti-inflammatory drugs). The Royal Adelaide Hospital and the University of Newcastle, located in Australia, have reported that fish oil has shown positive effects in the treatment of arthritis. In cases of osteoarthritis, fish oil can be helpful in reducing the impact of enzymes that destroy cartilage.
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.
Omega-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are essential nutrients that have potential preventive and therapeutic effects on psychiatric disorders, such as anxiety and depression,7-15 as well as comorbid depression and anxiety in physically ill patients,16-19 patients with coronary heart disease,20,21 and pregnant women.22,23 Preclinical data support the effectiveness of omega-3 PUFAs as treatment for anxiety disorders. Song et al24,25 found that an EPA-rich diet could reduce the development of anxiety-like behaviors in rats as well as normalize dopamine levels in the ventral striatum. In addition, Yamada et al26 showed that a high dietary omega-3 to omega-6 PUFA ratio reduced contextual fear behaviors in mice and that these effects were abolished by a cannabinoid CB1 receptor antagonist.
Hamazaki, K., Itomura, M., Huan, M., Nishizawa, H., Sawazaki, S., Tanouchi, M., Watanabe, S., Hamazaki, T., Terasawa, K., and Yazawa, K. Effect of omega-3 fatty acid-containing phospholipids on blood catecholamine concentrations in healthy volunteers: a randomized, placebo-controlled, double-blind trial. Nutrition 2005;21(6):705-710. 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]
Omega-3 fatty acids have been shown to increase platelet responsiveness to subtherapeutic anticoagulation therapies, including aspirin. Recently, it was noted that patient response to aspirin for anticoagulation therapy is widely variable (45), and, thus, the number of patients with a low response to aspirin or aspirin resistance is estimated to range from <1% to 45%, depending on many variables. However, in patients with stable coronary artery disease taking low-dose aspirin, EPA+DHA supplementation has been proven to be as effective as aspirin dose escalation to 325 mg/d for anticoagulation benefits (45). The antiplatelet drug clopidogrel has also been associated with hyporesponsiveness in some patients. This could be attributed to poor patient compliance, differences in genes and platelet reactivity, variability of drug metabolism, and drug interactions. More importantly, in 1 study, patients receiving standard dual antiplatelet therapy (aspirin 75 mg/d and clopidogrel 600-mg loading dose followed by 75 mg/d) were assigned to either EPA+DHA supplementation or placebo. After 1 mo of treatment, the P2Y12 receptor reactivity index (an indicator of clopidogrel resistance) was significantly lower, by 22%, for patients taking EPA+DHA compared with patients taking placebo (P = 0.020) (46).

The systematic review suggests that eating more ALA through food or supplements probably has little or no effect on cardiovascular deaths or deaths from any cause. However, eating more ALA probably reduces the risk of heart irregularities from 3.3 to 2.6%. The review team found that reductions in cardiovascular events with ALA were so small that about 1000 people would need to increase consumption of ALA for one of them to benefit. Similar results were found for cardiovascular death. They did not find enough data from the studies to be able to measure the risk of bleeding or blood clots from using ALA.


ODS seeks to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, supporting research, sharing research results, and educating the public. Its resources include publications (such as Dietary Supplements: What You Need to Know), fact sheets on a variety of specific supplement ingredients and products (such as vitamin D and multivitamin/mineral supplements), and the PubMed Dietary Supplement Subset
Have you also investigated the efficacy of purslane as a souce of Omega 3. Purslane (Portulaca olearacea) is a big part of the mountain vegetable diet of the Tujia minority in western Hunan (delicious), for example, and is consumed globally. Was glad to find it in local farmer’s market in California, and even happier to learn about its health benefits including Omega 3. The fish oil capsules are so huge… much better to sprinkle purslane or stir fry it…

The Department of Ecology of the State of Washington has ranked various seafood based on its EPA and DHA concentrations. The highest-ranking seafood is mackerel, excluding King mackerel, that has a concentration of 1,790 milligrams of combined EPA and DHA per 100 grams, followed by salmon at 1,590; bluefin tuna has between 1173 and 1504 milligrams; sardines contain 980 milligrams; albacore tuna has 862 milligrams; bass has 640 milligrams; tuna has 630 milligrams; trout and swordfish have 580 milligrams; and walleye has 530 milligrams. Other seafood, which includes sea bass, clams, lobster, scallops, catfish, cod, pollock, crayfish and scallops contains between 200 and 500 milligrams of EPA and DHA per 100 grams. Breaded fish products rank lowest on the list with only 0.26 milligram per 100 grams.
If you’ve been paying attention to health headlines over the last few decades, you’ve likely heard about essential fatty acids (EFAs) — specifically omega-3s and omega-6s. These nutrients play many vital roles in supporting our overall health, including increasing nutrient absorption, ensuring proper growth and development of the brain and nervous system, and reducing the risk of chronic illnesses, such as heart disease.  Click here for a guide to understanding omega-3 and omega-6 fatty acids and how they influence your health.
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.
Humans are unable to place double bonds beyond position 9 on long chain polyunsaturated fatty acids (FA), making the omega-3 FA synthesized in plants and in marine microalgae essential elements to the human diet.1 Fish contain high levels of 2 omega-3 FA, eicosapentaenoic acid (EPA; C20:5 n-3), and docosahexaenoic acid [DHA]; C22:6 n-3)2,3 (Fig. 1). Many claims about the role of these omega-3 FA have been made in the prevention and treatment of cardiovascular disease. For instance, fish oil is seen as having a therapeutic role in coronary artery disease (CAD), heart failure, fatal and nonfatal arrhythmias, as well as offering an alternative or adjunct to the standard therapy for hypertriglyceridemia and diabetes. This review will highlight the potential mechanisms of fish oil on cardiovascular disease and provide an update of clinical trial results. The established uses in the treatment of hypertriglyceridemia and sources of omega-3 FA—both dietary and drug therapy—will be iterated, along with its potential application in combination with standard hypolipidemic agents. Finally, the limitations of current data will be addressed, as well as suggested recommendations for clinical use.
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)
Most leafy green vegetables have significant amounts of omega-3, and spinach is no exception. Despite its villainous reputation, raw spinach actually has a mild flavor, making it an ideal base for salads or a crunchy addition to sandwiches. Many people add spinach to eggs, soups, or pasta dishes without impacting flavor. If you’re dealing with a particularly picky eater, though, try some of the recipes in Jessica Seinfeld’s Deceptively Delicious — her spinach and carrot brownies are tasty, healthy, and chocolaty to boot!
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
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.

However, since the dosage of fish oil required for an ideal effect in the improvement of a patient is unknown, the Arthritis Center in the Department of Rheumatology at John Hopkins University considers including omega-3 fatty acids and fish oil in the treatment of arthritis as controversial. The University also cautions that arthritis patients must be wary of all the other side effects that can come from using fish oil. You can read more about arthritis on the web page of the Arthritis Foundation and the Arthritis Center.
About the only exception are wild-caught Alaskan salmon and very small fish like sardines. The highest concentrations of mercury are found in large carnivorous fish like tuna, sea bass, and marlin. You may need to be especially cautious of canned tuna as well, as independent testing by the Mercury Policy Project found that the average mercury concentration in canned tuna is far over the "safe limits" of the Environmental Protection Agency (EPA).

CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.


In later life, cognitive function and brain deterioration may become a concern. Once again, maintaining high levels of EPA has been shown to lower the risk of developing and worsening cognitive decline and dementia. If, however, you know someone who already has a diagnosis of dementia or Alzheimer’s, their brain has already been damaged and needs structural support. At this point, DHA becomes important again and taking a high-EPA product that contains 250mg of DHA also is important to prevent further loss of brain tissue.
There’s evidence that points to the mechanism behind the effects of fish oil on body composition, showing that fat burning at rest is increased with 6 grams/day of fish oil supplementation, and additional research suggests that higher omega-3 levels may be helpful for enhancing satiety during weight loss efforts. Other evidence suggests that fat loss may be a side-effect of the reduction in inflammation that fish oil can help with. Any way you look at it, supporting your dietary habits with 4 or more grams of fish oil per day is probably a good idea!
Jatoi, A., Rowland, K., Loprinzi, C. L., Sloan, J. A., Dakhil, S. R., MacDonald, N., Gagnon, B., Novotny, P. J., Mailliard, J. A., Bushey, T. I., Nair, S., and Christensen, B. An eicosapentaenoic acid supplement versus megestrol acetate versus both for patients with cancer-associated wasting: a North Central Cancer Treatment Group and National Cancer Institute of Canada collaborative effort. J.Clin.Oncol. 6-15-2004;22(12):2469-2476. View abstract.

Animal studies show potent reduction of liver fat stores, glucose levels, and cholesterol levels in mice supplemented with krill oil while being fed a high fat diet.64,65 While many of these effects are seen with fish oil as well, studies show that krill oil, with its unique phospholipid structure, had the added benefit of increasing fat-burning in mitochondria while reducing new glucose production in the liver.66,67 As with so many other complex disease processes, utilizing multiple pathways to reduce disease is a highly effective strategy.67
My optometrist explained to me how important a good quality fish oil was to my eye health because I have dry eye due to inflammation. Little did I realize that it would be go for so many other things. Since I have been taking this product, not only have I had improvement with my dry eyes, but I have less joint pain from my osteoarthritis! I am so happy I found this and plan to continue it as part of my regular supplement routine! Thanks BioScience Nutrition!
Results of studies investigating the role of LCPUFA supplementation and LCPUFA status in the prevention and therapy of atopic diseases (allergic rhinoconjunctivitis, atopic dermatitis and allergic asthma) are controversial; therefore, at the present stage of our knowledge (as of 2013) we cannot state either that the nutritional intake of n−3 fatty acids has a clear preventive or therapeutic role, or that the intake of n-6 fatty acids has a promoting role in context of atopic diseases.[64]
ADD ADHD Ageing Allergies Alzheimer's Arthritis Autism baby Behaviour Brain function Cancer CFS Chronic Fatigue Concentration Dementia Depression Diabetes Digestion Dyslexia Dyspraxia Energy EPA Fertility Fibromyalgia General Health Good fats Healthy omega-3 Heart health Hormones IBS Immune System Inflammation Joints M.E. Mental health Mood Omega-3 Pregnancy Psoriasis Skin Sleep Stress Vegetarian nutrients Vegetarian Omega-3 Weight management
Soy can get a bad rap — and may indeed cause problems for people with certain food sensitivities — but this delicious bean is one of the most powerful (and versatile) ways to add omega-3 to your diet. Whole soybeans (known as edamame) are a favorite protein-packed snack for vegetarians; more processed forms (including tofu, soy milk, and soybean-based cooking oil) make soy infinitely more accessible. For some ideas, check out the 1998 classic, The Whole Soy Cookbook, which outlines how to cook with soy-based products ranging from miso to tempeh and beyond.
Fish oil is also extremely beneficial for pregnant women and their children. Throughout pregnancy and also while breastfeeding, a woman’s omega-3 needs are even higher than usual. According to the American Pregnancy Association, most U.S. women are deficient in EPA and especially DHA going into pregnancy and get even more depleted during pregnancy, as the placenta supplies the fetus with DHA from the mother’s tissue. Omega-3 DHA is a critical building block of the fetal brain, eyes and nervous system. Once the baby is born, omega-3s continue to be vital to healthy brain development and immune function. (30)
Stiefel, P., Ruiz-Gutierrez, V., Gajon, E., Acosta, D., Garcia-Donas, M. A., Madrazo, J., Villar, J., and Carneado, J. Sodium transport kinetics, cell membrane lipid composition, neural conduction and metabolic control in type 1 diabetic patients. Changes after a low-dose n-3 fatty acid dietary intervention. Ann Nutr Metab 1999;43(2):113-120. View abstract.
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