Finally, it is often assumed since there are not high levels of EPA in the brain, that it is not important for neurological function. Actually it is key for reducing neuro-inflammation by competing against AA for access to the same enzymes needed to produce inflammatory eicosanoids. However, once EPA enters into the brain it is rapidly oxidized (2,3). This is not the case with DHA (4). The only way to control cellular inflammation in the brain is to maintain high levels of EPA in the blood. This is why all the work on depression, ADHD, brain trauma, etc. have demonstrated EPA to be superior to DHA (5).
In many cases, people are recommended to consume fish oil because it is an easy way to get additional omega-3 fatty acids into their diet. Omega-3 fats can be used to reduce swelling or to prevent blood clots which could cause major cardiovascular damage. There are many other conditions which can be decreased or improved with the use of fish oil. In most cases fish oil is used to help reduce high triglycerides which can cause serious conditions like diabetes or heart disease.
The GISSI-Heart Failure trial was the first blinded, randomized trial to assess the efficacy of fish oil supplements in patients with heart failure.51 The trial enrolled 7046 subjects with heart failure; 60% with New York Heart Association class II symptoms and 40% with a history of MI. The majority of patients were on a standard heart failure regimen, including angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, beta-blockers, and spironolactone, but only 22% were on a statin. At an average of 3.9 years, the coprimary end points of death and death or hospital admission for cardiovascular reasons were reduced by approximately 9% with fish oil supplementation. Sudden cardiac death, a secondary end-point, showed a statistically nonsignificant relative risk reduction of 7% with fish oil. There was also a reduction in 2 other arrhythmia-related secondary end-points: first hospitalization for ventricular arrhythmia and presumed arrhythmic death.

Additional side effects of fish oil supplements which have been reported include headache, short-term memory loss, depression, somatic disorders, and increased risk of colon cancer, nasopharyngitis, worsening of asthma symptoms, hemolytic anemia, decreased physical activity, increased appetite, a general uncomfortable feeling or increased blood pressure. The percentage of users that develop these side effects is not known. If these side effects become severe it is recommended that you stop using fish oil supplements.
A healthy balance of dietary omega 6 and omega 3 fatty acids is a prerequisite for normal immune function, cognitive health, and cardiovascular health. Among other factors, sufficient dietary levels of EPA, DHA or other omega 3 fatty acids are also important in the regulation of normal blood lipoprotein and healthy cholesterol metabolism. Fish oil supplements can also lower elevated triglyceride levels, improving cardiovascular health and reducing the risk of heart disease.†
The contents of this website are for educational purposes and are not intended to offer personal medical advice. You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website. The Nutrition Source does not recommend or endorse any products.

Nielsen, A. A., Jorgensen, L. G., Nielsen, J. N., Eivindson, M., Gronbaek, H., Vind, I., Hougaard, D. M., Skogstrand, K., Jensen, S., Munkholm, P., Brandslund, I., and Hey, H. Omega-3 fatty acids inhibit an increase of proinflammatory cytokines in patients with active Crohn's disease compared with omega-6 fatty acids. Aliment.Pharmacol.Ther. 2005;22(11-12):1121-1128. 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.
Docosahexaenoic acid (DHA) found primarily in fish oil, this is the ultimate form of fatty acid in humans. Most people get far too little of this all-important fatty acid, especially since the conversion of ALA to DHA is slow and minimally yielding. Getting a daily dose of of DHA (600 to 1000 mg) from supplements is preferable to reap the health benefits. You have a choice of taking a fish oil supplement or one derived from algae or krill, a shrimp-like crustacean.
We are now fortunate to understand how these fats work in combination and in isolation, how they are digested, absorbed and utilised in the body, so we are able to tailor different blends of EPA and DHA according to the health benefits we are seeking to achieve. At Igennus, we have long specialised in the role of the omega-3 fatty acid EPA in clinical nutrition, as a powerful tool in the patient’s ‘toolkit’ for helping to regulate inflammation by restoring several biological markers, known as the omega-6 to omega-3 ratio and AA to EPA ratio. Before we discuss the therapeutic role of EPA in nutritional medicine, here’s a very brief summary of the role of both EPA and DHA in health throughout life.
Hanwell, H. E., Kay, C. D., Lampe, J. W., Holub, B. J., and Duncan, A. M. Acute fish oil and soy isoflavone supplementation increase postprandial serum (n-3) polyunsaturated fatty acids and isoflavones but do not affect triacylglycerols or biomarkers of oxidative stress in overweight and obese hypertriglyceridemic men. J Nutr 2009;139(6):1128-1134. View abstract.
Could you be deficient in omega-3s? The University of Maryland Medical Center says that the symptoms “include fatigue, poor memory, dry skin, heart problems, mood swings or depression, and poor circulation.” They also warn against a poor omega-3 to omega-6 ratio, cautioning readers that it may be “associated with worsening inflammation over time.” (6)
Keep in mind that APA found in plant-based foods takes a lot of energy for your body to convert to EPA and DHA. I understand that many people following a vegan diet struggle with the concept of fish oil or eating fish, but animal products contain the necessary omega-3 fatty acids to allow your body to absorb and synthesize what you take in. However, there are plant-based options — you’ll just need more APA because of the way your body processes the medium-chain fatty acid.
So why is an excess of DHA detrimental and an excess of EPA useful? DHA has a larger structure with two extra carbons and two extra double bonds, so it literally takes up more space in cell membranes than EPA. On the one hand, this is important because DHA plays a structural role in maintaining the fluidity of cell membranes ( essential for the normal function of proteins, channels and receptors that are also embedded in the membrane), but if a cell membrane becomes too saturated with DHA it can become too fluid, which can have a negative effect on cell function. EPA, on the other hand, is constantly utilised and always in demand.
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.
Dry eye. Higher intake of fish oil from the diet has been linked to a lower risk of dry eye in women. But the effects of fish oil in people with dry eye are inconsistent. Some research shows that fish oil reduces dry eye symptoms such as pain, blurred vision, and sensitivity. But fish oil doesn’t seem to improve other signs and symptoms of dry eye such as tear production and damage to the surface of the eye. Taking fish oil also doesn’t improve signs and symptoms of dry eye when used with other dry eye treatments.
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.
Omega 3 is a type of fat. Small amounts of omega 3 fats are essential for good health, and they can be found in the food that we eat. The main types of omega 3 fatty acids are; alpha­linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).  ALA is normally found in fats from plant foods, such as nuts and seeds (walnuts and rapeseed are rich sources). EPA and DHA, collectively called long chain omega 3 fats, are naturally found in fatty fish, such as salmon and fish oils including cod liver oil.

"All these diseases have a common genesis in inflammation," says Joseph C. Maroon, MD, professor and vice chairman of the department of neurological surgery at the University of Pittsburgh School of Medicine. Co-author of Fish Oil: The Natural Anti-Inflammatory, Maroon says that in large enough amountsomega-3's reduce the inflammatory process that leads to many chronic conditions.


The chemical structures of EPA and DHA are very similar and they compete for uptake and processing resources. During digestion, the triglyceride molecules in standard fish oil are broken down into a mono glycerol and two free fatty acids, small enough to be absorbed into cells of the gut lining. More often than not, DHA is the fatty acid that remains attached to the glycerol backbone, meaning in essence that DHA gets a ‘free pass’ into the gut, while the remaining free fatty acids (more often EPA) must reattach onto a glycerol molecule or risk being oxidised and used as fuel. The implication of this is that DHA levels in our cells are often concentrated at the expense of EPA after absorption when taking EPA and DHA in the standard ratio of 1.5 to 1.
Fish oil supplements came under scrutiny in 2006, when the Food Standards Agency in the UK and the Food Safety Authority of Ireland reported PCB levels that exceeded the European maximum limits in several fish oil brands,[60][61] which required temporary withdrawal of these brands. To address the concern over contaminated fish oil supplements, the International Fish Oil Standards (IFOS) Program, a third-party testing and accreditation program for fish oil products, was created by Nutrasource Diagnostics Inc. in Guelph, Ontario, Canada.[62]

Weak bones (osteoporosis). Research suggests that taking fish oil alone or together with calcium and evening primrose oil slows the rate of bone loss and increases bone density at the thigh bone (femur) and spine in elderly people with osteoporosis. But taking fish oil does not slow bone loss in older people with osteoarthritis in the knee but without weak bones.
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