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.
Anxiety, the most commonly experienced psychiatric symptom, is a psychological state derived from inappropriate or exaggerated fear leading to distress or impairment. The lifetime prevalence of any anxiety disorder is reported to be approximately 1 in 3.1 Anxiety is often comorbid with depressive disorders2 and is associated with lower health-related quality of life3 and increased risk of all-cause mortality.4 Treatment options include psychological treatments, such as cognitive-behavioral therapy and pharmacological treatments, mainly with selective serotonin reuptake inhibitors.5 Individuals with anxiety and related disorders tend to be more concerned about the potential adverse effects of pharmacological treatments (eg, sedation or drug dependence) and may be reluctant to engage in psychological treatments that can be time-consuming and costly, as well as sometimes limited in availability.6 Thus, evidence-based and safer treatments are required, especially for anxious patients with comorbid medical conditions.
Thanks for the informative article. You mentioned that those taking high doses of DHA should supplement it with trace amounts of GLA. What GLA source would you recommend, and how much per day? I will be taking around 3400 mg of epa and 2200 mg DHA per day. I've heard that Borage Oil is more potent in GLA than evening primrose, but that it can lead to increased clotting and increased risk of heart attack, stroke, etc due to increased thromboxane B2. The main reason I want to stay away from the primrose is because it is extremely rich in linoleic acid. Thanks.
Currently, there isn’t a set standard recommendation for how many omega-3s we need each day, but suggestions range from a fish oil dosage of 500 to 1,000 milligrams daily depending on whom you ask. How easy is it to get these recommended amounts? To give you an idea, there are more than 500 milligrams of total omega-3s in one can of tuna fish and one small serving of wild-caught salmon.
Fish and omega-3 fatty acids. If you keep up with the latest nutrition news, you may have a pretty good sense of what they offer. But, if you're like many people, you still can't tell your omega-3s from your omega-6s -- and you sure as heck can't pronounce eicosapentaenoic acid. That's OK. Our fishing expedition turned up some interesting facts to share about omega-3 fatty acids and fish.
Increased consumption of omega 3 fats is widely promoted globally because of a common belief that that it will protect against heart disease. There is more than one possible mechanism for how they might help prevent heart disease, including reducing blood pressure or reducing cholesterol. Omega 3 fats are readily available as over-the-counter supplements and they are widely bought and used.

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 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.
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…
Subgroup meta-analysis of the anxiolytic effects of omega-3 polyunsaturated fatty acids (PUFAs) based on different EPA percentages. The anxiolytic effects of omega-3 PUFAs were significant in the subgroup with an EPA percentage less than 60% (k, 11; Hedges g = 0.485; 95% CI, 0.017 to 0.954; P = .04) but not significant in the subgroups with an EPA percentage of at least 60% (k, 9; Hedges g, 0.092; 95% CI, –0.102 to 0.285; P = .35).

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.
3. DHA affects your child's learning and behavior. Do you want to maximize your child's intellectual potential? A study published in Plos One in June 20138 linked low levels of DHA with poorer reading, and memory and behavioral problems in healthy school-age children. In another study published in the American Journal of Clinical Nutrition in August 2013,9 children who consumed an omega-3 fat supplement as infants scored higher on rule learning, vocabulary, and intelligent testing at ages 3 to 5.
Cardiovascular disease is the cause of 38% of all deaths in the United States, many of which are preventable (28). Chronic inflammation is thought to be the cause of many chronic diseases, including cardiovascular disease (29). EPA and DHA are thought to have antiinflammatory effects and a role in oxidative stress (30) and to improve cellular function through changes in gene expression (31). In a study that used human blood samples, EPA+DHA intake changed the expression of 1040 genes and resulted in a decreased expression of genes involved in inflammatory and atherogenesis-related pathways, such as nuclear transcription factor κB signaling, eicosanoid synthesis, scavenger receptor activity, adipogenesis, and hypoxia signaling (31). Circulating markers of inflammation, such as C-reactive protein (CRP), TNF α, and some ILs (IL-6, IL-1), correlate with an increased probability of experiencing a cardiovascular event (32). Inflammatory markers such as IL-6 trigger CRP to be synthesized by the liver, and elevated levels of CRP are associated with an increased risk of the development of cardiovascular disease (33). A study of 89 patients showed that those treated with EPA+DHA had a significant reduction in high-sensitivity CRP (66.7%, P < 0.01) (33). The same study also showed a significant reduction in heat shock protein 27 antibody titers (57.69%, P < 0.05), which have been shown to be overexpressed in heart muscle cells after a return of blood flow after a period of ischemia (ischemia-reperfusion injury) and may potentially have a cardioprotective effect (33).
Those foods provide enormous amounts of other nutrients that are good for you. nSo it is way better to eat those foods than to take fish oil. With that said, some people find it very difficult to get vitamin A or vitamin D, and particularly for vitamin A, cod liver oil may be a very important source of that vitamin. Cod liver oil is a form of fish oil that happens to be high in the fat-soluble vitamins. Vitamin A is best found in liver. It’s better in my opinion to eat liver once a week, but there are a lot of people out there who are not going to eat liver once a week. So if you are using cod liver oil to get the vitamins that you can’t get from food—and I should point out that vitamin A can also be derived from plant foods, but many people genetically or for other reasons don’t derive it very well from plant foods.
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 supplements contain omega-3 fatty acids, the polyunsaturated oils prominent in fatty cold water fish like salmon, sardines and mackerel. In many observational studies, people who regularly consumed fish two or more times a week were less likely to suffer heart attacks, strokes and cardiovascular deaths than those who ate fish infrequently or not at all.

In 1964 it was discovered that enzymes found in sheep tissues convert omega−6 arachidonic acid into the inflammatory agent called prostaglandin E2[71] which both causes the sensation of pain and expedites healing and immune response in traumatized and infected tissues.[72] By 1979 more of what are now known as eicosanoids were discovered: thromboxanes, prostacyclins, and the leukotrienes.[72] The eicosanoids, which have important biological functions, typically have a short active lifetime in the body, starting with synthesis from fatty acids and ending with metabolism by enzymes. If the rate of synthesis exceeds the rate of metabolism, the excess eicosanoids may, however, have deleterious effects.[72] Researchers found that certain omega−3 fatty acids are also converted into eicosanoids, but at a much slower rate. Eicosanoids made from omega−3 fatty acids are often referred to as anti-inflammatory, but in fact they are just less inflammatory than those made from omega−6 fats. If both omega−3 and omega−6 fatty acids are present, they will "compete" to be transformed,[72] so the ratio of long-chain omega−3:omega−6 fatty acids directly affects the type of eicosanoids that are produced.[72]
EPA is the precursor to DHA in the body and can be converted to DHA with the enzyme delta-6 desaturase, but this process is inefficient in many people (much like the inefficiency of short-chain omega-3s to long-chain). For those individuals taking pure EPA products as well as those taking our EPA-rich products, we still recommend eating oily fish at least once each week to provide a natural source of DHA. Fish provides a unique nutritional package, supplying the diet with important amino acids (the building blocks of proteins) and antioxidants, including vitamins and minerals needed to process fats, so eating fish will also support the natural enzyme-dependent EPA to DHA conversion.
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]
Several large studies have linked higher blood levels of long-chain omega-3s with higher risks of prostate cancer. However, other research has shown that men who frequently eat seafood have lower prostate cancer death rates and that dietary intakes of long-chain omega-3s aren’t associated with prostate cancer risk. The reason for these apparently conflicting findings is unclear. 
Is krill oil better than fish oil for omega-3? Krill oil and fish oil are popular dietary supplements containing omega-3. Krill oil comes from a small crustacean while fish oil comes from oily fish, such as salmon. Both are shown to increase blood levels of omega-3 and have benefits for health. Learn more about the differences between krill oil and fish oil here. Read now

Yamagishi, K., Iso, H., Date, C., Fukui, M., Wakai, K., Kikuchi, S., Inaba, Y., Tanabe, N., and Tamakoshi, A. Fish, omega-3 polyunsaturated fatty acids, and mortality from cardiovascular diseases in a nationwide community-based cohort of Japanese men and women the JACC (Japan Collaborative Cohort Study for Evaluation of Cancer Risk) Study. J.Am.Coll.Cardiol. 9-16-2008;52(12):988-996. View abstract.

The omega-3 index is also important because it is inversely related to one’s omega-6 to omega-3 ratio — another important measurement (3). A lower omega-6/omega-3 ratio (meaning, you consume a balanced amount of these two fatty acid families) is associated with a reduced risk of many chronic diseases, including cardiovascular disease, cancer, and autoimmune disease, to name a few (4). Of course, most people get far too much omega-6 and too little omega-3, thanks to the plethora of highly processed foods in the Western diet.
A scientific review published in 2013 looked at omega-3 polyunsaturated fatty acids and prostate cancer prevention. Researchers concluded that there’s a great deal of evidence suggesting that omega-3s have antiproliferative effects – which means they inhibit cancer cell growth – in cancer cell lines, animal models and humans. In addition, the “direct effects on cancer cells” and indirect anti-inflammatory effects on the immune system fighting the cancer likely contribute to the ability of omega-3 fatty acids to inhibit tumor growth. (14)
These conversions occur competitively with omega−6 fatty acids, which are essential closely related chemical analogues that are derived from linoleic acid. They both utilize the same desaturase and elongase proteins in order to synthesize inflammatory regulatory proteins.[50] The products of both pathways are vital for growth making a balanced diet of omega−3 and omega−6 important to an individual's health.[77] A balanced intake ratio of 1:1 was believed to be ideal in order for proteins to be able to synthesize both pathways sufficiently, but this has been controversial as of recent research.[78]
We’ve already seen that fish oil can help with depression-like symptoms in rats, but what about people? A study published in the journal Nutritional Neuroscience evaluated the effects of fish oil supplementation on prefrontal metabolite concentrations in adolescents with major depressive disorder. Researchers found that there was a 40 percent decrease in major depression disorder symptoms in addition to marked improvements in amino acid and nutrition content in the brain, specifically, the right dorsolateral prefrontal cortex. (21)
We’ve written about the dose necessary to achieve measurable benefits before. However, a person’s actual omega-3 intake can be tricky to estimate. Even if you eat at least two servings of fatty fish per week, as the American Heart Association recommends (10), your fish might contain more or less omega-3s depending on the fish species, the time of year, and how you cook it. Even taking fish oil supplements isn’t always straightforward, as dose can be impacted by numerous bioavailability factors, as well as genetics, age, gender, medication-use and lifestyle.
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.
Fish oil has been shown to have a direct electrophysiological effect on the myocardium. Initial experience with animal ischemia models demonstrated that the ventricular fibrillation threshold was increased in both animals fed or infused with omega-3 FA.23,24 This progressed to a demonstration, on a cellular and ion channel level, that omega-3 FA reduce both sodium currents and L-type calcium currents.25–29 It is hypothesized that during ischemia, a reduction in the sodium ion current protects hyperexcitable tissue, and a reduction in the calcium ion current reduces arrhythmogenic depolarizing currents.30
Finally, in order for AA to be converted into inflammatory products it must be released from phospholipids (part of the cell membrane) using the enzyme phospholipase A2 and then converted by the enzyme cyclooxygenase. EPA utilises both of these enzymes, so if EPA levels are increased in the diet, it attracts enzyme away from AA to EPA – again giving rise to anti-inflammatory products instead of inflammatory ones.

To improve the health of your heart, brain, skin, hair, body and much, much more, consider adding fish oil to your daily supplement regime or consume wild-caught fish daily. If you’re adverse to fish oil pills, make sure to get at least two servings of fatty fish each week to fulfill your omega-3 needs and provide your body with fish oil benefits. This is a recommendation also encouraged by the American Heart Association. (38)
Dry eye. Some clinical research shows that eating more fish oil is linked to a lower risk of getting dry eye syndrome in women. Other research shows that taking a specific fish oil product (PRN Dry Eye Omega Benefits softgels) daily modestly improves symptoms of dry eye such as pain, blurred vision, and sensitivity. Other research using other forms of fish oil products suggests that taking these supplements for 4-12 weeks modest improves some dry eye symptoms. However, the sensation of eye dryness is not always improved. Other research also shows that taking a specific combination products containing fish oil and other ingredients might improve some dry eye symptoms; however, this research is conflicted and poor quality.
The question is whether the observed cardiovascular benefits often found among fish eaters is due solely to the oils in fish or to some other characteristics of seafood or to still other factors common to those who eat lots of fish, like eating less meat or pursuing a healthier lifestyle over all. Whatever the answer, it does not seem to be fish oil supplements.
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]
Fish oil is also used for diabetes, prediabetes, asthma, a movement and coordination disorder called dyspraxia, dyslexia, eczema, autism, obesity, weak bones (osteoporosis), rheumatoid arthritis (RA), osteoarthritis, psoriasis, an autoimmune disease called systemic lupus erythematosus (SLE), multiple sclerosis, HIV/AIDS, cystic fibrosis, gum disease, Lyme disease, sickle cell disease, and preventing weight loss caused by some cancer drugs.