Eicosatetraenoic Acid (ETA): ETA is a lesser-known omega-3 fatty acid that also contains 20 carbons, like EPA, but only four bonds instead of five. It is found richly inroe oil and green-lipped mussel and is only recently being recognized for its potent health benefits. Not only is it anti-inflammatory, like the other omega-3s, but ETA can also limit your body’s production of the inflammatory omega-6 fatty acid arachidonic acid (ARA). In fact, ETA redirects the enzyme that normally creates ARA to convert it to EPA instead!

Retinol (Vitamin A) B vitamins: Thiamine (B1) Riboflavin (B2) Niacin (B3) Pantothenic acid (B5) Pyridoxine (B6) Biotin (B7) Folic acid (B9) Cyanocobalamin (B12) Ascorbic acid (Vitamin C) Ergocalciferol and Cholecalciferol (Vitamin D) Tocopherol (Vitamin E) Naphthoquinone (Vitamin K) Calcium Choline Chromium Cobalt Copper Fluorine Iodine Iron Magnesium Manganese Molybdenum Phosphorus Potassium Selenium Sodium Sulfur Zinc


The differing actions of EPA and DHA, together with their competitive uptake, help to explain why studies that attempt to use standard fish oil therapeutically (where DHA and EPA are combined, in a natural ratio of approximately 1.5:1) are either less beneficial than expected, or even completely ineffective. Standard EPA/DHA fish oils are more suitable for everyday wellbeing, to compensate for a lack of fish in the diet and to meet a suggested intake.
FDA pregnancy category C. It is not known whether Fish Oil will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using Fish Oil. It is not known whether omega-3 polyunsaturated fatty acids pass into breast milk or if this could harm a nursing baby. Do not use Fish Oil without telling your doctor if you are breast-feeding a baby. Do not give this medication to anyone under 18 years old.

The information on this website has not been evaluated by the Food & Drug Administration or any other medical body. We do not aim to diagnose, treat, cure or prevent any illness or disease. Information is shared for educational purposes only. You must consult your doctor before acting on any content on this website, especially if you are pregnant, nursing, taking medication, or have a medical condition.


Gorjao, R., Verlengia, R., Lima, T. M., Soriano, F. G., Boaventura, M. F., Kanunfre, C. C., Peres, C. M., Sampaio, S. C., Otton, R., Folador, A., Martins, E. F., Curi, T. C., Portiolli, E. P., Newsholme, P., and Curi, R. Effect of docosahexaenoic acid-rich fish oil supplementation on human leukocyte function. Clin Nutr 2006;25(6):923-938. View abstract.
The three types of omega−3 fatty acids involved in human physiology are α-linolenic acid (ALA), found in plant oils, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), both commonly found in marine oils.[2] Marine algae and phytoplankton are primary sources of omega−3 fatty acids. Common sources of plant oils containing ALA include walnut, edible seeds, clary sage seed oil, algal oil, flaxseed oil, Sacha Inchi oil, Echium oil, and hemp oil, while sources of animal omega−3 fatty acids EPA and DHA include fish, fish oils, eggs from chickens fed EPA and DHA, squid oils, and krill oil. Dietary supplementation with omega−3 fatty acids does not appear to affect the risk of death, cancer or heart disease.[4][5] Furthermore, fish oil supplement studies have failed to support claims of preventing heart attacks or strokes or any vascular disease outcomes.[6][7]
Brain function and vision rely on dietary intake of DHA to support a broad range of cell membrane properties, particularly in grey matter, which is rich in membranes.[61][62] A major structural component of the mammalian brain, DHA is the most abundant omega−3 fatty acid in the brain.[63] It is under study as a candidate essential nutrient with roles in neurodevelopment, cognition, and neurodegenerative disorders.[61]

42. Cawood AL, Ding R, Napper FL, Young RH, Williams JA, Ward MJ, Gudmundsen O, Vige R, Payne SP, Ye S, et al. Eicosapentaenoic acid (EPA) from highly concentrated n-3 fatty acid ethyl esters is incorporated into advanced atherosclerotic plaques and higher plaque EPA is associated with decreased plaque inflammation and increased stability. Atherosclerosis. 2010;212:252–9. [PubMed]


Most people get far too little omega-3s in their diet. In fact, research consistently indicates that the majority of Americans have just slightly more than half the amount of EPA and DHA in their tissues than they need for optimum brain and body health. This is partly due to a high dietary intake of unhealthy fats combined with an inadequate intake of EPA and DHA.
Between the ages of five and 65, the majority of the body’s needs can be met by using EPA-rich oils and eating fish, marine products, organic greens and pastured animal products. EPA levels are under constant demand and low EPA levels in adolescents and adults correlates strongly with development of mental health issues, including depression, dyslexia and dyspraxia, heart problems, joint and bone conditions, as well as neurodegenerative diseases such as MS and Parkinson’s. EPA also protects our genes and cell cycle, as well as helping to keep our stress response regulated, so an adequate supply of EPA throughout adult life can help prevent a range of chronic illness.
In comparison, the omega-3s found in krill appear to be more rapidly incorporated into red blood cell phospholipids.7 This is important, because not only do scientists view the uptake of essential fatty acids in red blood cells as a biomarker for uptake into the brain,8 but additional research suggests that when omega-3 fatty acids such as DHA are bound to phospholipids as they are with krill, it increases their uptake to the brain.9 This is further supported by human clinical research, which suggests ingestion of phospholipid-bound EPA and DHA increase cognitive function scores to a greater degree compared with scores obtained when the fatty acids in the ingested oil were provided in the triglycerides storage form.10
In 2016, AHRQ reviewed 143 studies that evaluated the effects of giving omega-3 supplements to pregnant or breastfeeding women or giving formulas with added DHA to infants. They found that when women took omega-3 supplements during pregnancy, their babies’ birth weight was slightly higher, but the risk of an undesirably low birth weight did not change. Also, when women took omega-3 supplements during pregnancy, their pregnancies lasted a little longer, but there was no effect on the risk of premature birth. Omega-3s were not found to have effects on any other aspects of the mothers’ or infants’ health or the infants’ long-term development. Aspects of the infants’ health that were not shown to be affected by omega-3s include growth after birth, visual acuity, long-term neurological and cognitive development, and the risks of autism, ADHD, learning disorders, and allergies.
Fish oil supplements vary in the amounts and ratios of DHA and EPA they contain. For example, salmon oil naturally contains more DHA than EPA; a supplement derived from algae may only contain DHA. Krill oil contains significant amounts of both EPA and DHA. Read the labels and remember whatever supplement you buy, it must have at least 600 mg of DHA.
To exclude the possible confounding effects of clinical variables on the Hedges g, metaregression analysis was conducted with an unrestricted maximum likelihood random-effects model of single variables when there were more than 10 data sets available. Specifically, the clinical variables of interest included mean age, female proportion, sample size, mean body mass index, daily omega-3 PUFA dosage, EPA to DHA ratio, treatment duration, dropout rate, and others. In addition, a subgroup meta-analysis was conducted to investigate potential sources of heterogeneity, specifically, a further subgroup meta-analysis focused on those trials that were placebo controlled or non–placebo controlled. To more clearly uncover the differences in the meta-analysis results among the recruited studies, a further subgroup meta-analysis was performed according to the presence of a specific clinical diagnosis or no specific clinical condition, mean omega-3 PUFA daily dosage, and mean age. In addition, in a previous study, the EPA percentage (ie, ≥60%) in the PUFA regimens had different effects on depression treatment.9 Therefore, we also arranged the subgroup meta-analysis based on the EPA percentage. Furthermore, we arranged subgroup meta-analysis procedures only when there were at least 3 data sets included.45 To investigate the potentially different estimated effect sizes between subgroups, we performed an interaction test and calculated the corresponding P values.46
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.

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…
Although GOED has used diligent care to ensure that the information provided on this website is accurate and up to date, we make no representation or warranty of the accuracy, reliability or completeness of this information. The website is intended to educate and inform readers about omega-3 fatty acids and is not meant to constitute or provide medical advice, diagnosis or treatment and is distributed without warranty of any kind, either expressly or implied. In no event shall GOED be liable for any damages arising from the reader’s reliance upon, or use of, these materials. The reader shall be solely responsible for any interpretation or use of material contained herein. The content of this document is subject to change without further notice.

However, in both observational studies and controlled clinical trials, eating fish was shown to foster optimal development of a baby’s brain and nervous system, prompting advice that pregnant women and nursing mothers eat more fish rich in omega-3s while avoiding species that may contain mercury or other contaminants like PCBs sometimes found in freshwater fish.
Gorjao, R., Verlengia, R., Lima, T. M., Soriano, F. G., Boaventura, M. F., Kanunfre, C. C., Peres, C. M., Sampaio, S. C., Otton, R., Folador, A., Martins, E. F., Curi, T. C., Portiolli, E. P., Newsholme, P., and Curi, R. Effect of docosahexaenoic acid-rich fish oil supplementation on human leukocyte function. Clin Nutr 2006;25(6):923-938. View abstract.
Fish oil contains two very important omega-3 PUFAs. I’m talking about docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). DHA and EPA are sometimes called the marine omega-3s because they mainly come from fish. Some of the best fish to eat to obtain fish oil from in your diet include wild-caught salmon, herring, white fish, sardines and anchovies.
Scientific studies have found that fish oil can help to prevent and kill various cancers, including colon, prostate and breast. (13a) Not only has research proven that it makes conventional cancer drugs more effective, but it’s also an effective stand-alone therapy in natural cancer treatment. Intravenous fish oil lipid emulsions, in particular, are rich in omega-3 polyunsaturated fatty acids, which exhibit anti-inflammatory and immunomodulatory effects. (13b)
Kremer, J. M., Lawrence, D. A., Petrillo, G. F., Litts, L. L., Mullaly, P. M., Rynes, R. I., Stocker, R. P., Parhami, N., Greenstein, N. S., Fuchs, B. R., and . Effects of high-dose fish oil on rheumatoid arthritis after stopping nonsteroidal antiinflammatory drugs. Clinical and immune correlates. Arthritis Rheum. 1995;38(8):1107-1114. View abstract.

Science is dynamic, not static, and as scientific understanding advances scientists sometimes have to modify their positions. Dr. Kidd’s position on EPA and DHA has now changed due to advances in the clinical and basic scientific research. Though the brain carries predominantly DHA and very little EPA, clinical trial results clearly indicate EPA has benefit for mood and probably other higher brain functions. At the basic science level, it has become clear that both EPA and DHA, not DHA alone, are required for the brain to make new nerve cells. Dr. Kidd very closely monitors the research on EPA and… Read more »

People who eat seafood rich in EPA and DHA at least once a week are less likely to die of heart disease, according to the National Center for Complementary and Alternative Medicine. The fatty acids may also be helpful in relieving symptoms of rheumatoid arthritis. Fish oil has been rated as "Effective" by MedlinePlus for lowering high triglycerides, which can be a major risk factor for heart disease. Fish oil has been rated as "Likely Effective" for keeping healthy hearts free of disease. Although eating baked or broiled fish can reduce the risk of heart disease, fried fish or fish sandwiches not only cancel out any heart-healthy benefits, but may also contribute to heart disease, MedlinePlus notes.

Although results from studies regarding the disease processes of AD seem to be promising, there are conflicting data regarding the use of omega-3 fatty acids in terms of cognitive function. Neuropsychiatric symptoms accompany AD from early stages and tend to increase with the progression of the disease (55). An analysis of 174 patients randomized to a placebo group or to a group with mild to moderate AD (MMSE score ≥15) treated with daily DHA (1.7 g) and EPA (0.6 g) found that at 6 mo, the decline in cognitive function did not differ between the groups. Yet, in a subgroup with very mild cognitive dysfunction (n = 32, MMSE score >27), they observed a significant reduction in the MMSE decline rate in the DHA+EPA-supplemented group compared with the placebo group (47). Another study that looked at DHA supplementation in individuals with mild to moderate AD used the Alzheimer's Disease Assessment Scale–Cognitive subscale, which evaluates cognitive function on a 70-point scale in terms of memory, attention, language, orientation, and praxis. This study found that DHA supplementation had no beneficial effect on cognition during the 18-mo trial period for the DHA group vs. placebo (56).
Omega-3 FA most likely reduce serum triglyceride levels by modulating very-low-density lipoprotein (VLDL) and chylomicron metabolism. There is a consistent finding in the literature that the end effect of fish oil is decreased hepatic secretion of VLDL17—the major endogenous source of triglycerides. This effect occurs most likely through multiple mechanisms, including: (1) decreased synthesis of triglycerides because these omega-3 FA may not be the preferred substrates of the enzyme diacylglycerol O-acyltransferase,18 or they may interact with nuclear transcription factors that control lipogenesis19; cellular metabolism consequently shifts toward a decrease in triglyceride synthesis and an increase in FA oxidation; and (2) the promotion of apolipoprotein B degradation in the liver through the stimulation of an autophagic process.20 This means that fewer VLDL particles can be assembled and secreted. Fish oil may also accelerate VLDL and chylomicron clearance21 by inducing lipoprotein lipase activity.22
Before getting to know some of the fish oil side effects, you have to know more about fish oil, like its benefits and usages. Fish oil has become a popular supplement for athletes, as well as those looking to improve their overall health. Many claims have been made regarding the improvements to the body which can be made by using fish oil to increase the body's level of fatty omega-3 acids. Some of these claims have been backed up by studies, while others have not been proven with significant scientific evidence. There are also some precautions that need to be addressed if you will be taking fish oil regularly. People with certain health conditions may see a worsening of their symptoms if they increase their intake of fatty acids too quickly or with the wrong products.

Human growth and intellectual development – DHA plays a very important role during fetal development, early infancy and old age. High concentrations of DHA are found in the brain and increase 300 to 500 percent in an infant’s brain during the last trimester of pregnancy. Adding DHA to a pregnant mother’s diet may be beneficial for the fetus’s brain development. Elderly people should also take EPA DHA, because as we get older, our bodies form less EPA and DHA, which may cause less mental focus and cognitive function. Taking EPA DHA also may help with mental abnormalities, such as Alzheimer’s disease and dementia.
Secondary prevention fish oil studies demonstrate a significant reduction in MI. But unfortunately, both the observational and randomized trials were conducted in an era before the widespread use of HMG-CoA reductase inhibitors, and therefore, the incremental benefit is still unknown. Nevertheless, in patients receiving antiplatelet and anticoagulant therapy in addition to fish oil supplementation (even at doses as high as 4 g per day), no serious adverse complications have been reported.
The absence of DHA in many pure EPA trials, and therefore lack of competition between EPA and DHA during digestion and consequently for uptake, is considered to be partly responsible for the positive outcomes. Simply put, pure EPA delivers more EPA into cells where it is needed than combined EPA & DHA blends. Consequently, oils containing DHA may not be suitable for a variety of conditions when treatment relies on increasing levels of EPA and its end products.
In 2016, AHRQ reviewed 143 studies that evaluated the effects of giving omega-3 supplements to pregnant or breastfeeding women or giving formulas with added DHA to infants. They found that when women took omega-3 supplements during pregnancy, their babies’ birth weight was slightly higher, but the risk of an undesirably low birth weight did not change. Also, when women took omega-3 supplements during pregnancy, their pregnancies lasted a little longer, but there was no effect on the risk of premature birth. Omega-3s were not found to have effects on any other aspects of the mothers’ or infants’ health or the infants’ long-term development. Aspects of the infants’ health that were not shown to be affected by omega-3s include growth after birth, visual acuity, long-term neurological and cognitive development, and the risks of autism, ADHD, learning disorders, and allergies.

Jump up ^ Talakoub, Lily; Neuhaus, Isaac M.; Yu, Siegrid S. (2008). "Chapter 2: Cosmoceuticals". In Alam, Murad; Gladstone, Hayes B.; Tung, Rebecca. Cosmetic Dermatology. Requisites in dermatology. Elsevier Health Sciences. p. 9. ISBN 9780702031434. Retrieved 2014-10-23. Other oils used as emollients include fish oil, petrolatum, shea butter, and sunflower seed oil.
The human body does not produce significant amounts of EPA or DHA on its own, so you must get these important nutrients from the foods you eat and the supplements you consume. If you’re looking to get the heart health benefits of omega-3s, go straight to the source of EPA and DHA. EPA and DHA are naturally found in marine sources, including fatty fish – salmon, tuna, mackerel, herring – shellfish, and marine algae.
To reap all the omega-3 benefits, it may be difficult for some people to eat the required amounts of oily fish, particularly with the well-known dangers of farmed fish, which are more readily available to most Americans. That’s why some people consider a high-quality omega-3 supplement in addition to a well-rounded diet. I’ll discuss supplements in a moment, though.

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!
Jump up ^ Martins, Julian G (2009). "EPA but Not DHA Appears to Be Responsible for the Efficacy of Omega-3 Long Chain Polyunsaturated Fatty Acid Supplementation in Depression: Evidence from a Meta-Analysis of Randomized Controlled Trials". Journal of the American College of Nutrition. 28 (5): 525–42. doi:10.1080/07315724.2009.10719785. PMID 20439549.
Dyerberg, J., Eskesen, D. C., Andersen, P. W., Astrup, A., Buemann, B., Christensen, J. H., Clausen, P., Rasmussen, B. F., Schmidt, E. B., Tholstrup, T., Toft, E., Toubro, S., and Stender, S. Effects of trans- and n-3 unsaturated fatty acids on cardiovascular risk markers in healthy males. An 8 weeks dietary intervention study. Eur.J.Clin.Nutr. 2004;58(7):1062-1070. View abstract.

People used to believe that osteoporosis and osteoarthritis were the result of aging and reduced intake of calcium and milk products. Science has now shown that these bone and joint disorders are, in part, due to inflammation. Because of this, bones and joints are prime targets for the anti-inflammatory properties of omega-3 oils from both fish and krill.


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.
Children, in particular, seem to experience problems with sleep when they don’t get enough omega-3 fatty acids in their diets. In adults, low omega-3 levels are associated with obstructive sleep apnea. One reason for this may be that low omega-3s are linked to lower levels of melatonin, the hormone partly responsible for helping you to get to sleep in the first place.
The National High Blood Pressure Education Program in the United States has cautioned against inaccurate publicity of fish oil as an effective means of lowering high blood pressure in patients suffering from hypertension. According to its report, fish oil supplements lower blood pressure in a very small way in hypertensive patients. Research conducted at the Channing Laboratory in Boston has revealed that moderate doses of fish oil supplements have little effect on the condition of high blood pressure in normotensive people.
Not surprising, there are some areas in which both EPA and DHA appear to be equally beneficial. As an example, both are equally effective in reducing triglyceride levels (10). This is probably due to the relatively equivalent activation of the gene transcription factor (PPAR alpha) that causes the enhanced synthesis of the enzymes that oxidize fats in lipoprotein particles. There is also apparently equal activation of the anti-inflammatory gene transcription factor PPAR-gamma (11). Both seem to be equally effective in making powerful anti-inflammatory eicosanoids known as resolvins (12). Finally, although both have no effect on total cholesterol levels, DHA can increase the size of LDL particle to a greater extent than can EPA (10).
The ultimate goal of using omega-3 fatty acids is the reduction of cellular inflammation. Since eicosanoids derived from arachidonic acid (AA), an omega-6 fatty acid, are the primary mediators of cellular inflammation, EPA becomes the most important of the omega-3 fatty acids to reduce cellular inflammation for a number of reasons. First, EPA is an inhibitor of the enzyme delta-5-desaturase (D5D) that produces AA (1). The more EPA you have in the diet, the less AA you produce. This essentially chokes off the supply of AA necessary for the production of pro-inflammatory eicosanoids (prostaglandins, thromboxanes, leukotrienes, etc.). DHA is not an inhibitor of this enzyme because it can’t fit into the active catalytic site of the enzyme due to its larger spatial size. As an additional insurance policy, EPA also competes with AA for the enzyme phospholipase A2 necessary to release AA from the membrane phospholipids (where it is stored). Inhibition of this enzyme is the mechanism of action used by corticosteroids. If you have adequate levels of EPA to compete with AA (i.e. a low AA/EPA ratio), you can realize many of the benefits of corticosteroids but without their side effects. That’s because if you don’t release AA from the cell membrane then you can’t make inflammatory eicosanoids. Because of its increased spatial dimensions, DHA is not a good competitor of phospholipase A2 relative to EPA. On the other hand, EPA and AA are very similar spatially so they are in constant competition for the phospholipase A2 enzyme just as both fatty acids are in constant competition for the delta-5 desaturase enzyme. This is why measuring the AA/EPA ratio is such a powerful predictor of the state of cellular inflammation in your body.

Tanaka, K., Ishikawa, Y., Yokoyama, M., Origasa, H., Matsuzaki, M., Saito, Y., Matsuzawa, Y., Sasaki, J., Oikawa, S., Hishida, H., Itakura, H., Kita, T., Kitabatake, A., Nakaya, N., Sakata, T., Shimada, K., and Shirato, K. Reduction in the recurrence of stroke by eicosapentaenoic acid for hypercholesterolemic patients: subanalysis of the JELIS trial. Stroke 2008;39(7):2052-2058. View abstract.
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