6. Krauss-Etschmann S, Shadid R, Campoy C, Hoster E, Demmelmair H, Jimenez M, Gil A, Rivero M, Veszpremi B, Decsi T, et al. Effects of fish-oil and folate supplementation of pregnant women on maternal and fetal plasma concentrations of docosahexaenoic acid and eicosapentaenoic acid: a European randomized multicenter trial. Am J Clin Nutr. 2007;85:1392–400. [PubMed]
AAKG β-hydroxy β-methylbutyrate Carnitine Chondroitin sulfate Cod liver oil Copper gluconate Creatine/Creatine supplements Dietary fiber Echinacea Elemental calcium Ephedra Fish oil Folic acid Ginseng Glucosamine Glutamine Grape seed extract Guarana Iron supplements Japanese Honeysuckle Krill oil Lingzhi Linseed oil Lipoic acid Milk thistle Melatonin Red yeast rice Royal jelly Saw palmetto Spirulina St John's wort Taurine Wheatgrass Wolfberry Yohimbine Zinc gluconate
Thanks to fatdog11 for that informative post about PCB’s in fish-oil supplements. Are these same toxicity levels found in fish themselves, or possibly are these levels so high only in highly concentrated fish-oil products? Also, can fatdog11 please inform us more about algae-derived omega-3. What are the DHA and EPA levels in these capsules? What is the cost, and where can they be purchased?
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.
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.
Why would someone foul a perfectly good box of rotini with omega 3 oils? This is based on the belief that omega 3 fatty acids reduce heart disease and vascular risk, probably through reducing blood pressure and cholesterol. This is a plausible claim, but as we see over and over again in medicine, plausibility (while nice) is insufficient as a basis for clinical claims.

First, EPA inhibits the enzyme that produces arachidonic acid. Second, EPA impedes the release of arachidonic acid from cell membranes (where it is stored) and its metabolization once it is released. Without this release and metabolization, your body can’t make eicosanoids. The result is lower risk of the inflammation that would have been caused by all that arachidonic acid going to eicosanoids.
So back to fish oil in general. The major fish oil benefits include decreasing the risk of heart disease and stroke while also helping reduce symptoms of depression, hypertension, attention deficit hyperactivity disorder (ADHD), joint pain, arthritis and chronic skin ailments like eczema. (2) Fish oil intake has also been associated with aiding the body in weight loss, fertility, pregnancy and increased energy. Prescription fish oil has even been approved by the FDA to lower unhealthy high triglyceride levels. (3)

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.

For slowing weight loss in patients with cancer: 30 mL of a specific fish oil product (ACO Omega-3, Pharmacia, Stockholm, Sweden) providing 4.9 grams of EPA and 3.2 grams of DHA daily for 4 weeks has been used. 7.5 grams of fish oil daily providing EPA 4.7 grams and DHA 2.8 grams has been used for about 6 weeks. In addition, two cans of a fish oil nutritional supplement containing 1.09 grams of EPA and 0.96 grams of DHA per can have been used daily for up to 7 weeks.
^ Jump up to: a b Hooper L, Thompson RL, Harrison RA, Summerbell CD, Ness AR, Moore HJ, Worthington HV, Durrington PN, Higgins JP, Capps NE, Riemersma RA, Ebrahim SB, Davey Smith G (2006). "Risks and benefits of omega−3 fats for mortality, cardiovascular disease, and cancer: systematic review". BMJ. 332 (7544): 752–60. doi:10.1136/bmj.38755.366331.2F. PMC 1420708. PMID 16565093. Retrieved 2006-07-07.[permanent dead link]
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.
This constant sweeping motion of DHA also causes the breakup of lipid rafts in membranes (8). Disruption of these islands of relatively solid lipids makes it more difficult for cancer cells to continue to survive and more difficult for inflammatory cytokines to initiate the signaling responses to turn on inflammatory genes (9). In addition, the greater spatial characteristics of DHA increase the size of LDL particles to a greater extent compared to EPA. As a result, DHA helps reduce the entry of these enlarged LDL particles into the muscle cells that line the artery thus reducing the likelihood of developing atherosclerotic lesions (10). Thus the increased spatial territory swept out by DHA is good news for making certain areas of membranes more fluid or lipoprotein particles larger, even though it reduces the benefits of DHA in competing with AA for key enzymes important in the development of cellular inflammation.
Fish oil is effective in reducing inflammation in the blood and tissues. Regular consumption of fish oil supplements, tablets, pills, and capsules is helpful to those who suffer from chronic inflammatory diseases. Fish oil is effective in treating gastrointestinal disorders, Celiac disease, short bowel syndrome and inflammatory bowel disease (IBD) including Crohn’s Disease and ulcerative colitis, which are both typical disorders of the intestine. Patients suffering from Crohn’s disease often find it difficult to absorb vitamins, fats, and essential supplements. Fish oil supplements are an effective diet for such patients.
The studies examining the possible benefits of omega-3s continue. Researchers are looking at a range of health outcomes and the impact of a heart healthy diet rich in omega 3 fatty acids on a range of chronic disease. For instance, Dr. Hooper's team is beginning to evaluate the effects that omega-3 fats may have on diabetes, dementia, and some cancers.
However, the researchers do have some good news. They concluded that omega 3 fatty acids do appear to reduce the type of blood cholesterol known as triglycerides, but that supplements probably are not useful for preventing or improving heart and circulatory problems. And, upping your intake of plant-based omega 3s high in ALA (ie, walnuts, flaxseed and flax oil, chia seeds) may help your heart somewhat.2

Metagenics offers a wide range of educational opportunities including webinars, group meetings, and seminars as part of our commitment to continuing functional medicine education. Our goal is to give our practitioners further insight to help address their patients’ unique health needs for a higher level of personalized, lifetime wellness care. We have been sharing this ever-growing body of nutritional and lifestyle research for over 25 years.

Fish oil supplement studies have failed to support claims of preventing heart attacks or strokes.[3][4][5][6] Earlier, in 2007, the American Heart Association had recommended the consumption of 1 gram of fish oil daily, preferably by eating fish, for patients with coronary artery disease, but cautioned pregnant and nursing women to avoid eating fish with high potential for mercury contaminants including mackerel, shark, and swordfish.[32] (Optimal dosage was related to body weight.)
However, this difference in the length of the carbon chain gives these two types of omega-3s significant characteristics. EPA and DHA are long-chain fatty acids, while ALA is a short-chain fatty acid. The long-chain fatty acids are more important for cellular health. Another omega-3 fat, docosapentaenoic acid (DPA) can also be better synthesized by your body by elongating EPA.
Unintended weight loss is a problem that many patients with AD may face, and EPA+DHA supplementation has had a positive effect on weight gain in patients with AD. In a study using EPA+DHA supplementation, patients' weight significantly increased by 0.7 kg in the EPA+DHA treatment group at 6 mo (P = 0.02) and by 1.4 kg at 12 mo (P < 0.001) and was observed mainly in patients with a BMI <23 at the study start (54). This means that those patients with a lower BMI preferentially gained weight compared with those patients already with a higher BMI.
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.
If you get your omega-3 index measured, you’ll know if your current efforts are sufficient. And this knowledge is especially important given that even health-conscious people are not always self-aware. One survey found that in a group of people with omega-3 index levels in the intermediate risk range, some 30% believed they were consuming enough omega-3s (11). One registered dietitian wrote a compelling story about exactly this experience. She discovered she was in the intermediate range, in spite of her intentions to eat enough fish.
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. 
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]
Many people focus on the dosage of fish oil to take, like 1000 mg or 1200 mg, but it is the omega-3s that matter. This is where the benefits of fish oil are found. The two types of omega-3 fatty acids to focus on are EPA and DHA. These omega-3s are naturally found in oily fish like salmon, halibut, sardines and anchovies, and are the very reason why fish oil supplements have received such high praise.
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.
Jump up ^ Crowe, Francesca L.; Appleby, Paul N.; Travis, Ruth C.; Barnett, Matt; Brasky, Theodore M.; Bueno-de-Mesquita, H. Bas; Chajes, Veronique; Chavarro, Jorge E.; Chirlaque, Maria-Dolores (2014-09-01). "Circulating fatty acids and prostate cancer risk: individual participant meta-analysis of prospective studies". Journal of the National Cancer Institute. 106 (9): dju240. doi:10.1093/jnci/dju240. ISSN 1460-2105. PMC 4188122. PMID 25210201.

DHA is especially vital for infant and child brain and nervous system development, as well as visual function. In older children, high DHA levels have been shown to improve learning ability, while deficiencies have been linked to learning problems and ADHD. And in adults, some studies have shown that DHA helps protect against cognitive decline and Alzheimer’s disease.
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
Many studies show that eating fatty fish and other types of seafood as part of a healthy eating pattern helps keep your heart healthy and helps protect you from many heart problems. Getting more EPA or DHA from foods lowers triglyceride levels, for example. Omega-3 dietary supplements can also help lower triglyceride levels, but it is not clear whether omega-3 supplements protect you from most heart problems.
Some high-quality omega-3 supplements will have lower amounts than EPA/DHA but accompany them with digestive enzymes. While it looks counterintuitive on a nutrition label, this is often done because there is debate about how much of the omega-3’s you actually absorb from supplements when taken alone. By coupling omega-3’s with a digestive enzyme blend, you are likely able to absorb more of the nutrient without having to consume as many grams.
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.
The hypotriglyceridemic effect of fish oil is well established and is related to both dose and baseline triglyceride level. Patients with triglycerides <90 mg/dL will be negligibly affected unless very high doses of omega-3 FA are used.67,68 However, in patients with triglycerides >200 mg/dL, who are treated with 4 g/d of fish oil, a 30% reduction in triglycerides is expected.17,69 For patients with triglycerides >500 mg/dL who are at risk for pancreatitis, the National Cholesterol Education Program Adult Treatment Panel III guidelines recommend using fish oil supplements as an adjunctive therapy to fibrates and nicotinic acid.70 Lovaza capsules have been shown to be effective, safe, and comparable to gemfibrozil in treating triglycerides at this range.71,72 The official label recommendation for Lovaza is for patients with triglycerides >500 mg/dL.73

Omega−3 fatty acids are formed in the chloroplasts of green leaves and algae. While seaweeds and algae are the source of omega−3 fatty acids present in fish, grass is the source of omega−3 fatty acids present in grass fed animals.[134] When cattle are taken off omega−3 fatty acid rich grass and shipped to a feedlot to be fattened on omega−3 fatty acid deficient grain, they begin losing their store of this beneficial fat. Each day that an animal spends in the feedlot, the amount of omega−3 fatty acids in its meat is diminished.[135]
Heart disease. Research suggests that eating fish can be effective for keeping people with healthy hearts free of heart disease. People who already have heart disease might also be able to lower their risk of dying from heart disease by eating fish. The picture is less clear for fish oil supplements. For people who already take heart medications such as a "statin" and those who already eat a decent amount of fish, adding on fish oil might not offer any additional benefit.

A 2012 study involved children from 6 to 12 years of age with ADHD who were being treated with methylphenidate and standard behavior therapy for more than six months. The parents of these children reported no improvement in behavior and academic learning using these standard treatments. The researchers randomly gave some of the children an omega-3 and omega-6 acid supplementation or a placebo. They found “statistically significant improvement” for the omega group in the following categories: restlessness, aggressiveness, completing work and academic performance. (5)

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.
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!
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
Five studies with 7 data sets recruited participants without specific clinical conditions.36,47,51,55,60 The main results revealed that there was no significant difference in the association of treatment with reduced anxiety symptoms between patients receiving omega-3 PUFA treatment and those not receiving it (k, 5; Hedges g, –0.008; 95% CI, –0.266 to 0.250; P = .95) (Figure 3A). Fourteen studies with 14 data sets recruited participants with specific clinical diagnoses.33-35,48-50,52-54,56-59,61 The main results revealed a significantly greater association of treatment with reduced anxiety symptoms in patients receiving omega-3 PUFA treatment than in those not receiving it (k, 14; Hedges g, 0.512; 95% CI, 0.119-0.906; P = .01) (Figure 3A). Furthermore, according to the interaction test, the association of omega-3 PUFA treatment with reduced anxiety symptoms was significantly stronger in subgroups with specific clinical diagnoses than in subgroups without specific clinical conditions (P = .03).

A, Subgroup meta-analysis of the anxiolytic effect of omega-3 polyunsaturated fatty acids (PUFAs) based on an underlying specific clinical diagnosis or not. The anxiolytic effect of omega-3 PUFAs was not significant in the subgroup of participants without specific clinical conditions (k, 5; Hedges g, –0.008; 95% CI, –0.266 to 0.250; P = .95) but was significant in the subgroup of participants with specific clinical diagnoses (k, 14; Hedges g, 0.512; 95% CI, 0.119-0.906; P = .01). Furthermore, the association of treatment with reduced anxiety symptoms of omega-3 PUFAs were significantly stronger in subgroups with specific clinical diagnoses than in subgroups without specific clinical conditions (P = .03). B, Subgroup meta-analysis of the anxiolytic effect of omega-3 PUFAs based on different mean omega-3 PUFA dosages. The anxiolytic effect of omega-3 PUFAs was not significant in subgroups of mean omega-3 PUFA dosages less than 2000 mg/d (k, 9; Hedges g, 0.457; 95% CI, –0.077 to 0.991; P = .09) but was significant in the subgroup of mean omega-3 PUFA dosage of at least 2000 mg/d (k, 11; Hedges g, 0.213; 95% CI, 0.031-0.395; P = .02).
^ Jump up to: a b Aursand, Marit; Mozuraityte, Revilija; Hamre, Kristin; Knutsen, Helle; Maage, Amund; Arukwe, Augustine (2011). Description of the processes in the value chain and risk assessment of decomposition substances and oxidation products in fish oils (PDF). Norwegian Scientific Committee for Food Safety. ISBN 978-82-8259-035-8. Retrieved 19 October 2012.[page needed]
This article had several limitations and the findings need to be considered with caution. First, our participant population is too heterogeneous because of our broad inclusion criteria, which might be true if considering current Diagnostic and Statistical Manual of Mental Disorders or International Classification of Diseases diagnostic systems. However, the novel Research Domain Criteria consider anxiety to be one of the major domains in Negative Valence Systems. Trials should be conducted in populations in which anxiety is the main symptom irrespective of the presence or absence of diagnosis of anxiety disorder. Second, because of the limited number of recruited studies and their modest sample sizes, the results should not be extrapolated without careful consideration. Third, the significant heterogeneity among the included studies (Cochran Q, 178.820; df, 18; I2, 89.934%; P < .001) with potential influence by some outlier studies, such as the studies by Sohrabi et al56 and Yehuda et al,61 would be another major concern. Therefore, clinicians should pay attention to this aspect when applying the results of the current meta-analysis to clinical practice, particularly when considering the subgroups of these 2 studies (ie, subgroups with specific clinical diagnoses, with <2000 mg/d, with EPA <60%, and with placebo-controlled trials).

Marchioli, R., Barzi, F., Bomba, E., Chieffo, C., Di, Gregorio D., Di, Mascio R., Franzosi, M. G., Geraci, E., Levantesi, G., Maggioni, A. P., Mantini, L., Marfisi, R. M., Mastrogiuseppe, G., Mininni, N., Nicolosi, G. L., Santini, M., Schweiger, C., Tavazzi, L., Tognoni, G., Tucci, C., and Valagussa, F. Early protection against sudden death by n-3 polyunsaturated fatty acids after myocardial infarction: time-course analysis of the results of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI)-Prevenzione. Circulation 4-23-2002;105(16):1897-1903. View abstract.

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).

Hamazaki, K., Syafruddin, D., Tunru, I. S., Azwir, M. F., Asih, P. B., Sawazaki, S., and Hamazaki, T. The effects of docosahexaenoic acid-rich fish oil on behavior, school attendance rate and malaria infection in school children--a double-blind, randomized, placebo-controlled trial in Lampung, Indonesia. Asia Pac.J Clin Nutr 2008;17(2):258-263. View abstract.
6. Krauss-Etschmann S, Shadid R, Campoy C, Hoster E, Demmelmair H, Jimenez M, Gil A, Rivero M, Veszpremi B, Decsi T, et al. Effects of fish-oil and folate supplementation of pregnant women on maternal and fetal plasma concentrations of docosahexaenoic acid and eicosapentaenoic acid: a European randomized multicenter trial. Am J Clin Nutr. 2007;85:1392–400. [PubMed]

The way that fish oil does that is to interfere with carbohydrate metabolism, and in insulin-resistant people or in people with specific genetic differences that might predispose them to having very high triglycerides, you do benefit from interfering that pathway with the fish oil, but I would actually try a low-carbohydrate diet in a lot of those situations to see if that helps with lowering triglycerides, or in the case of insulin resistance, I would try to address the insulin resistance at its root cause.
A certain kidney disease called IgA nephropathy. Some research shows that long-term but not short-term use of fish oil can slow the loss of kidney function in high-risk patients with IgA nephropathy. Fish oil might have greater effects when taken at higher doses. Also, it might be most effective in people with IgA nephropathy who have higher levels of protein in the urine.