Fish oil

A typical fish oil softgel

Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), precursors of eicosanoids that are known to reduce inflammation throughout the body,^[1][2] and are thought to have many health benefits.^{[by whom?]}

Fish do not actually produce omega-3 fatty acids, but instead accumulate them by consuming either microalgae or prey fish that have accumulated omega-3 fatty acids, together high quantity of antioxidants as iodide and selenium, from microalgae, where these antioxidants are able to protect the fragile polyunsaturated lipids from peroxidantion ^{[3] [3][4][5]}. Fatty predatory fish like sharks, sword fish, tilefish, and albacore tuna may be high in omega-3 fatty acids, but due to their position at the top of the food chain, these species can also accumulate toxic substances (see biomagnification). For this reason, the U.S. Food and Drug Administration recommends limiting consumption of certain (predatory) fish species (e.g. albacore tuna, shark, king mackerel, tilefish and swordfish) due to high levels of toxic contaminants such as mercury, dioxin, PCBs and chlordane.^[6] Fish oil is used as a component in aquaculture feed. More than 50 percent of the world's fish oil used in aquaculture feed is fed to farmed salmon.^[7]

The omega-3 fatty acids in fish oil are thought to be beneficial in treating hypertriglyceridemia, and possibly beneficial in preventing heart disease.^[8] Fish oil and omega-3 fatty acids have been studied in a wide variety of other conditions, such as clinical depression,^[9][10] anxiety,^[11][12][13] cancer, and macular degeneration, although benefit in these conditions remains to be proven.^[8]

Production

In 2005, fish oil production declined in all main producing countries with the exception of Iceland. The 2005 production estimate is about 570,000 tonnes in the five main exporting countries (Peru, Denmark, Chile, Iceland and Norway), a 12% decline from the 650,000 tonnes produced in 2004.^{[citation needed]}. Peru continues to be the main fish oil producer worldwide, with about one fourth of total fish oil production.

Grams of omega-3 fatty acids per 3oz (85g) serving of popular fish.^[14]

Common name	grams
Tuna	0.21–1.1
Tuna (canned, light)	0.17-0.24
Pollock	0.45
Salmon	1.1–1.9
Cod	0.15–0.24
Catfish	0.22–0.3
Flounder	0.48
Grouper	0.23
Halibut	0.60–1.12
Mahi mahi	0.13
Orange roughy	0.028
Red snapper	0.29
Shark	0.83
Swordfish	0.97
Tilefish	0.90
King mackerel	0.36

Benefits

See also: Coronary heart disease, Health benefits, and health risks of Omega 3 fatty acids

Cancer

Several studies report possible anti-cancer effects of n−3 fatty acids found in fish oil (particularly breast, colon and prostate cancer).^[15][16][17] Omega-3 fatty acids reduced prostate cancer growth, slowed histopathological progression, and increased survival in genetically engineered mice.^[18] Among n-3 fatty acids (omega-3), neither long-chain nor short-chain forms were consistently associated with reduced breast cancer risk. High levels of docosahexaenoic acid, however, the most abundant n-3 polyunsaturated fatty acid (omega-3) in erythrocyte membranes, were associated with a reduced risk of breast cancer.^[19] In a recent study of 35,000 middle-aged women published in the journal Cancer Epidemiology, those that took fish oil supplements were found to have a 32% lower risk of breast cancer, although the study authors stressed that the result was preliminary and that "we should not draw any conclusions about a causal relationship."^[20]

Cardiovascular

A 2008 meta-study by the Canadian Medical Association Journal found fish oil supplementation did not demonstrate any preventative benefit to cardiac patients with ventricular arrhythmias.^[21]

The American Heart Association recommends the consumption of 1g of fish oil daily, preferably by eating fish, for patients with coronary heart disease although pregnant and nursing women are advised to avoiding eating fish with high potential for mercury contaminants including mackerel, shark, or swordfish.^[22] Note that optimal dosage relates to body weight.^{[citation needed]}

The US National Institutes of Health lists three conditions for which fish oil and other omega-3 sources are most highly recommended: hypertriglyceridemia, secondary cardiovascular disease prevention and high blood pressure. It then lists 27 other conditions for which there is less evidence. It also lists possible safety concerns: "Intake of 3 grams per day or greater of omega-3 fatty acids may increase the risk of bleeding, although there is little evidence of significant bleeding risk at lower doses. Very large intakes of fish oil/omega-3 fatty acids may increase the risk of hemorrhagic (bleeding) stroke."^[8]

Mental health

Studies published in 2004 and 2009 have suggested that the n-3 EPA may reduce the risk of depression and suicide. One such study^[23] took blood samples of 100 suicide-attempt patients and compared the blood samples to those of controls and found that levels of Eicosapentaenoic acid were significantly lower in the washed red blood cells of the suicide-attempt patients. A small American trial, published in 2009, suggests that E-EPA, as monotherapy, might treat major depressive disorder, however the study achieved no statistical significance.^[24]

Studies^[25][26] were conducted on prisoners in England where the inmates were fed seafood which contains omega-3 fatty acids. The higher consumption of these fatty acids corresponded with a drop in the assault rates. Another Finnish study found that prisoners who were convicted of violence had lower levels of omega–3 fatty acids than prisoners convicted of nonviolent offenses. It was suggested that these kinds of fatty acids are responsible for the neuronal growth of the frontal cortex of the brain which, it is further alleged, is the seat of personal behavior.^{[citation needed]}

A study from the Orygen Research Centre in Melbourne suggests that omega-3 fatty acids could also help delay or prevent the onset of schizophrenia. The researchers enlisted 81 'high risk' young people aged 13 to 24 who had previously suffered brief hallucinations or delusions and gave half of them capsules of fish oil while the other half received fish-tasting dummy substitute. One year on, only three percent of those on fish oil had developed schizophrenia compared to 28 percent from those on the substitute.^[27] A study conducted at Sheffield University in England reported positive results with fish oil on patients suffering from schizophrenia. Dr. Malcolm Peet, Professor of Psychiatry at Sheffield University organized the study and followed the progress of the participants. Participants of the study were previously taking anti-psychotic prescription drugs but after some time were no longer effective on patients. After taking fish oil supplements, participants in the study experienced progress compared to others who were given a placebo.^[28][29]

However, the largest controlled study to date found no cognitive benefit after two years in the elderly.^[30][31]

Alzheimer's disease

According to a study from Louisiana State University in September 2005, Docosahexaenoic acid, an omega-3 fatty acid often found in fish oil, may help protect the brain from cognitive problems associated with Alzheimer's disease.^[32]

Lupus

In the Northern Ireland study, lupus disease activity, especially in the skin and joints was significantly reduced in the patients who received the fish oil supplements, at both the 12-week and 24-week follow-up periods. No such reduction was seen in the lupus disease activity of the patients who got the placebo. There were also changes in the blood platelets of the patients who took the fish oil supplements, with an increase in proteins that are considered anti-inflammatory and a decrease in proteins that promote inflammation; these changes were not evident in the group that took placebo. The fish oil group showed an increase in FMD, which the researchers took as a sign that the omega-3 oils were helping the cells in the blood vessel walls to remain healthy.

Parkinson's disease

A study^[33] examining whether omega-3 exerts neuroprotective action in Parkinson's disease found that it did, using an experimental model, exhibit a protective effect (much like it did for Alzheimer's disease). The scientists exposed mice to either a control or a high omega-3 diet from two to twelve months of age and then treated them with a neurotoxin commonly used as an experimental model for Parkinson's. The scientists found that high doses of omega-3 given to the experimental group completely prevented the neurotoxin-induced decrease of dopamine that ordinarily occurs. Since Parkinson's is a disease caused by disruption of the dopamine system, this protective effect exhibited could show promise for future research in the prevention of Parkinson's disease.^{[citation needed]}

Depression

Evidence regarding the efficacy of fish oil supplements as a treatment for depression is currently inconclusive. Whereas several methodologically rigorous studies have reported statistically significant positive effects in the treatment of depressed patients, other studies have found effects to be small or insignificant.^{[citation needed]}

For example, an August 2003 double-blind placebo-controlled study published in the journal European Neuropsychopharmacology found that among 28 patients with major depressive disorder, "patients in the omega-3 PUFA group had a significantly decreased score on the 21-item Hamilton Rating Scale for Depression than those in the placebo group."^[9] Another study in the American Journal of Psychiatry reported that the addition of fish oil supplements to regular maintenance anti-depression therapy conferred "highly significant" benefits by the third week of the trial.^[13]

In contrast, a 2005 randomized double-blind placebo-controlled study conducted under the auspices of the New Zealand Institute for Crop & Food Research found "no evidence that fish oil improved mood when compared to the placebo oil, despite an increase in circulating ω-3 polyunsaturated fatty acids."^[34] Similarly, another scholarly study published in October 2007 reported that fish oil supplements conferred no additional benefits beyond those conferred by standard treatment.^[35]

Psoriasis

Diets supplemented with cod liver oil have also shown beneficial effects on psoriasis.^[36] Though it has not been proven, some claim that fish oil also improves the tone of the skin and the condition of the blood vessels. More studies would have to be done to understand whether this is true.^{[citation needed]}

Pregnancy

Omega-3 polyunsaturated fatty acids (commonly found in fish oil) protect against fetal brain injury and promotes fetal and infant brain health.^[37] Some studies reported better psycho motor development at 30 months of age in infants whose mothers received fish oil supplements for the first four months of lactation.^[38] In addition, five-year-old children whose mothers received modest algae based docosahexaenoic acid supplementation for the first 4 months of breastfeeding performed better on a test of sustained attention. This suggests that docosahexaenoic acid intake during early infancy confers long-term benefits on specific aspects of neurodevelopment.^[38]

Docosahexaenoic acid supplementation has also been found to be essential for early visual development of the baby.^[39] However, the standard western diet is severely deficient in these critical nutrients. This omega-3 dietary deficiency, a nutrient found in fish oil, is compounded by the fact that pregnant women become depleted in omega-3s, since the fetus uses omega-3s for its nervous system development. Omega-3s are also used after birth if they are provided in breast milk.^[40]

In addition, provision of fish oil during pregnancy may reduce an infant’s sensitization to common food allergens and reduce the prevalence and severity of certain skin diseases in the first year of life. This effect may persist until adolescence with a reduction in prevalence and/or severity of eczema, hay fever and asthma.^[41]

Omega-3 fatty acid supplementation is also beneficial to the mother.^[37] It has been shown to prevent pre-term labor and delivery.^[40] It is recommended that women who are breastfeeding consume fish oil at least twice a week, although the American Heart Association recommends pregnant and nursing women are to avoiding eating fish with high potential for mercury contaminants including mackerel, shark, or swordfish.^[41]

Dangers

Vitamins

The liver and liver products (such as cod liver oil) of fish and many animals (such as seals and whales) contain omega-3, but also the active form of vitamin A. At high levels, this form of the vitamin can be dangerous (Hypervitaminosis A).^{[citation needed]}

Toxic pollutants

Fish oil supplements have sometimes come under scrutiny in recent years. In early 2006, government agencies such as the Food Standards Agency in the UK and the Food Safety Authority of Ireland reported PCB levels that exceeded the strict new European maximum limits in several fish oil brands,^[42][43] which required temporary withdrawal of these brands. To address the growing concern over contaminated fish oil supplements, the International Fish Oil Standards program, a voluntary review process, was created at University of Guelph.^[44]

Patented production purification processes do however exist in order to remove pollutants and dioxins from fish oil to levels far below the EU limits.^{[citation needed]}

EU regulations have set a limit on the percentage of toxins that can be present in the oil for it to still be beneficial to the consumer. Recently, concerns in the UK and Ireland with regards to upholding the limits set have resulted in some major manufacturers taking their products off the market on a temporary basis.^{[citation needed]}

A March 2010 lawsuit filed by a California environmental group claims that eight popular brands of fish oil supplements contained excessive levels of PCBs, including CVS/pharmacy, Nature Made, Rite Aid, GNC, Solgar, Twinlab, Now Health, Omega Protein and Pharmavite.^[45][46]

It should be noted, however, that the majority of these products were either cod liver or shark liver oils. Because the liver is the major filtering and detoxifying organ, PCB content will be much higher in such products than in the more common fish oil produced from the processing of whole fish.^{[citation needed]}

An analysis based on data from the Norwegian Women and Cancer Study (NOWAC) with regards to the dangers of persistent organic pollutants (POPs) in cod liver came to the conclusion that "in Norwegian women, fish liver consumption was not associated with an increased cancer risk in breast, uterus, or colon. In contrast, a decreased risk for total cancer was found."^[47]

See also

• Lovaza

Notes

1. ^ Moghadasian, Mohammed H. (2008). "Advances in Dietary Enrichment with N-3 Fatty Acids". Critical Reviews in Food Science and Nutrition 48 (5): 402–10. doi:10.1080/10408390701424303. PMID 18464030. 
2. ^ Cleland, Leslieg; James, Michaelj; Proudman, Susannam (2006). Arthritis Research & Therapy 8: 679–81. doi:10.1186/ar1876. PMC 1526555. PMID 16542466. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1526555. 
3. ^ ^{a b} Venturi S, Donati FM, Venturi A, Venturi M (2000). "Environmental iodine deficiency: A challenge to the evolution of terrestrial life?". Thyroid 10 (8): 727–9. doi:10.1089/10507250050137851. PMID 11014322. 
4. ^ Venturi S, Venturi M (2007). "Evolution of Dietary Antioxidant Defences". European Epi-Marker 11 (3): 1–12. http://www.icb-asbl.com/en/pdf/epimarker/epimarker_3_07.pdf. 
5. ^ Küpper FC, Carpenter LJ, McFiggans GB, et al. (2008). "Iodide accumulation provides kelp with an inorganic antioxidant impacting atmospheric chemistry" (Free full text). Proceedings of the National Academy of Sciences of the United States of America 105 (19): 6954–8. doi:10.1073/pnas.0709959105. PMC 2383960. PMID 18458346. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2383960. 
6. ^ EPA (2007-01-31). "Fish Consumption Advisories". http://www.epa.gov/mercury/advisories.htm. Retrieved 2007-02-08. 
7. ^ FAO: World Review of Fisheries and Aquaculture 2008: Highlights of Special Studies Rome.
8. ^ ^{a b c} NIH Medline Plus. "MedlinePlus Herbs and Supplements: Omega-3 fatty acids, fish oil, alpha-linolenic acid". http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-fishoil.html. Retrieved 2006-02-14. 
9. ^ ^{a b} Su, Kuan-Pin; Huang, Shih-Yi; Chiu, Chih-Chiang; Shen, Winston W. (2003). "Omega-3 fatty acids in major depressive disorder". European Neuropsychopharmacology 13 (4): 267–71. doi:10.1016/S0924-977X(03)00032-4. PMID 12888186. 
10. ^ Naliwaiko, K.; Araújo, R.L.F.; Da Fonseca, R.V.; Castilho, J.C.; Andreatini, R.; Bellissimo, M.I.; Oliveira, B.H.; Martins, E.F. et al. (2004). "Effects of Fish Oil on the Central Nervous System: A New Potential Antidepressant?". Nutritional Neuroscience 7 (2): 91–9. doi:10.1080/10284150410001704525. PMID 15279495. 
11. ^ Green, Pnina; Hermesh, Haggai; Monselise, Assaf; Marom, Sofi; Presburger, Gadi; Weizman, Abraham (2006). "Red cell membrane omega-3 fatty acids are decreased in nondepressed patients with social anxiety disorder". European Neuropsychopharmacology 16 (2): 107–13. doi:10.1016/j.euroneuro.2005.07.005. PMID 16243493. 
12. ^ Yehuda, Shlomo; Rabinovitz, Sharon; Mostofsky, David I. (2005). "Mixture of essential fatty acids lowers test anxiety". Nutritional Neuroscience 8 (4): 265–7. doi:10.1080/10284150500445795. PMID 16491653. 
13. ^ ^{a b} Nemets, B.; Stahl, Z; Belmaker, RH (2002). "Addition of Omega-3 Fatty Acid to Maintenance Medication Treatment for Recurrent Unipolar Depressive Disorder". American Journal of Psychiatry 159 (3): 477–9. doi:10.1176/appi.ajp.159.3.477. PMID 11870016. 
14. ^ "Fish, Levels of Mercury and Omega-3 Fatty Acids". American Heart Association. http://www.americanheart.org/presenter.jhtml?identifier=3013797. Retrieved October 6, 2010. 
15. ^ Augustsson, Katarina; Michaud, Dominique S.; Rimm, Eric B.; Leitzmann, Michael F.; Stampfer, Meir J.; Willett, Walter C.; Giovannucci, Edward (2003). "A Prospective Study of Intake of Fish and Marine Fatty Acids and Prostate Cancer". Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology 12 (1): 64–7. PMID 12540506. http://cebp.aacrjournals.org/cgi/pmidlookup?view=long&pmid=12540506. 
16. ^ De Deckere, E A M (1999). "Possible beneficial effect of fish and fish n-3 polyunsaturated fatty acids in breast and colorectal cancer". European Journal of Cancer Prevention 8 (3): 213–21. doi:10.1097/00008469-199906000-00009. PMID 10443950. 
17. ^ Caygill, C P J; Hill, M J (1995). "Fish, n-3 fatty acids and human colorectal and breast cancer mortality". European Journal of Cancer Prevention 4 (4): 329–32. doi:10.1097/00008469-199508000-00008. PMID 7549825. 
18. ^ Berquin, Isabelle M.; Min, Younong; Wu, Ruping; Wu, Jiansheng; Perry, Donna; Cline, J. Mark; Thomas, Mike J.; Thornburg, Todd et al. (2007). "Modulation of prostate cancer genetic risk by omega-3 and omega-6 fatty acids". Journal of Clinical Investigation 117 (7): 1866–75. doi:10.1172/JCI31494. PMC 1890998. PMID 17607361. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1890998. 
19. ^ Pala, V.; Krogh, V; Muti, P; Chajès, V; Riboli, E; Micheli, A; Saadatian, M; Sieri, S et al. (2001). "Erythrocyte Membrane Fatty Acids and Subsequent Breast Cancer: a Prospective Italian Study". Journal of the National Cancer Institute 93 (14): 1088–95. doi:10.1093/jnci/93.14.1088. PMID 11459870. 
20. ^ Laurance, Jeremy (2010-07-08). "Fish supplements may reduce risk of cancer". The Independent (London). http://www.independent.co.uk/life-style/health-and-families/health-news/fish-supplements-may-reduce-risk-of-cancer-2021147.html. 
21. ^ Nair, G. M.; Connolly, S. J. (2008). "Should patients with cardiovascular disease take fish oil?". Canadian Medical Association Journal 178 (2): 181–2. doi:10.1503/cmaj.071654. PMC 2174997. PMID 18195293. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2174997. 
22. ^ "Fish and Omega-3 Fatty Acids". American Heart Association. http://www.americanheart.org/presenter.jhtml?identifier=4632. Retrieved 2007-02-09. 
23. ^ Huan, M; Hamazaki, K; Sun, Y; Itomura, M; Liu, H; Kang, W; Watanabe, S; Terasawa, K et al. (2004). "Suicide attempt and n-3 fatty acid levels in red blood cells: A case control study in china". Biological Psychiatry 56 (7): 490–6. doi:10.1016/j.biopsych.2004.06.028. PMID 15450784. 
24. ^ Mischoulon, David; Papakostas, George I.; Dording, Christina M.; Farabaugh, Amy H.; Sonawalla, Shamsah B.; Agoston, A. Monica; Smith, Juliana; Beaumont, Erin C. et al. (2009). "A Double-Blind, Randomized Controlled Trial of Ethyl-Eicosapentaenoate for Major Depressive Disorder". The Journal of Clinical Psychiatry 70 (12): 1636–44. doi:10.4088/JCP.08m04603. PMC 2918427. PMID 19709502. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2918427. 
25. ^ STEPHEN MIHM (2006-04-16). "Does Eating Salmon Lower the Murder Rate?". NYTimes. http://www.nytimes.com/2006/04/16/magazine/16wwln_idealab.html?ex=1302840000&en=42040a1da92a9fe6&ei=5090&partner=rssuserland&emc=rss. Retrieved 2007-02-08. 
26. ^ Gesch, C. B.; Hammond, SM; Hampson, SE; Eves, A; Crowder, MJ (2002). "Influence of supplementary vitamins, minerals and essential fatty acids on the antisocial behaviour of young adult prisoners: Randomised, placebo-controlled trial". The British Journal of Psychiatry 181: 22–8. doi:10.1192/bjp.181.1.22. PMID 12091259. 
27. ^ Amminger, G. P.; Schafer, M. R.; Papageorgiou, K.; Klier, C. M.; Cotton, S. M.; Harrigan, S. M.; MacKinnon, A.; McGorry, P. D. et al. (2010). "Long-Chain  -3 Fatty Acids for Indicated Prevention of Psychotic Disorders: A Randomized, Placebo-Controlled Trial". Archives of General Psychiatry 67 (2): 146–54. doi:10.1001/archgenpsychiatry.2009.192. PMID 20124114. 
28. ^ http://www.one-tcn.com/1812/schizophrenia-naturally/
29. ^ Inman, K "Is Fish Oil The Cure" The Independent. Retrieved 1998-05-26 [1]
30. ^ Dangour, AD; Allen, E; Elbourne, D; Fasey, N; Fletcher, AE; Hardy, P; Holder, GE; Knight, R et al. (2010). "Effect of 2-y n−3 long-chain polyunsaturated fatty acid supplementation on cognitive function in older people: a randomized, double-blind, controlled trial". American Journal of Clinical Nutrition 91 (6): 1725–1732. doi:0.3945/​ajcn.2009.29121. http://www.ajcn.org/content/91/6/1725.full. 
31. ^ Fish oil 'no benefit' to elderly NHS, 29 April 2010.
32. ^ Lukiw, W. J.; Cui, JG; Marcheselli, VL; Bodker, M; Botkjaer, A; Gotlinger, K; Serhan, CN; Bazan, NG (2005). "A role for docosahexaenoic acid-derived neuroprotectin D1 in neural cell survival and Alzheimer disease". Journal of Clinical Investigation 115 (10): 2774–83. doi:10.1172/JCI25420. PMC 1199531. PMID 16151530. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1199531. 
33. ^ Bousquet, M.; Saint-Pierre, M.; Julien, C.; Salem, N.; Cicchetti, F.; Calon, F. (2007). "Beneficial effects of dietary omega-3 polyunsaturated fatty acid on toxin-induced neuronal degeneration in an animal model of Parkinson's disease". The FASEB Journal 22 (4): 1213–25. doi:10.1096/fj.07-9677com. PMID 18032633. 
34. ^ Silvers, K; Woolley, C; Hamilton, F; Watts, P; Watson, R (2005). "Randomised double-blind placebo-controlled trial of fish oil in the treatment of depression". Prostaglandins, Leukotrienes and Essential Fatty Acids 72 (3): 211–218. doi:10.1016/j.plefa.2004.11.004. 
35. ^ Grenyer, B; Crowe, T; Meyer, B; Owen, A; Grigonisdeane, E; Caputi, P; Howe, P (2007). "Fish oil supplementation in the treatment of major depression: A randomised double-blind placebo-controlled trial". Progress in Neuro-Psychopharmacology and Biological Psychiatry 31 (7): 1393–6. doi:10.1016/j.pnpbp.2007.06.004. PMID 17659823. 
36. ^ Wolters, M. (2005). "Diet and psoriasis: experimental data and clinical evidence". British Journal of Dermatology 153 (4): 706–14. doi:10.1111/j.1365-2133.2005.06781.x. PMID 16181450. 
37. ^ ^{a b} Zhang, W.; Hu, X.; Yang, W.; Gao, Y.; Chen, J. (2010). "Omega-3 Polyunsaturated Fatty Acid Supplementation Confers Long-Term Neuroprotection Against Neonatal Hypoxic-Ischemic Brain Injury Through Anti-Inflammatory Actions". Stroke 41 (10): 2341–7. doi:10.1161/STROKEAHA.110.586081. PMC 3021248. PMID 20705927. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3021248. 
38. ^ ^{a b} Jensen, Craig L.; Voigt, Robert G.; Llorente, Antolin M.; Peters, Sarika U.; Prager, Thomas C.; Zou, Yali L.; Rozelle, Judith C.; Turcich, Marie R. et al. (2010). "Effects of Early Maternal Docosahexaenoic Acid Intake on Neuropsychological Status and Visual Acuity at Five Years of Age of Breast-Fed Term Infants". The Journal of Pediatrics 157 (6): 900–5. doi:10.1016/j.jpeds.2010.06.006. PMID 20655543. 
39. ^ Institute of Medicine, National Academy of Science (2005). Dietary reference intakes for energy, carbohydrates, fiber, fat, fatty acids, cholesterol, protein and amino acids (Macronutrients). The National Academies Press, Washington DC [2]
40. ^ ^{a b} American Pregnancy Association. N.p., Aug. 2009
41. ^ ^{a b} Calder, Philip C.; Kremmyda, Lefkothea-Stella; Vlachava, Maria; Noakes, Paul S.; Miles, Elizabeth A. (2010). "Is there a role for fatty acids in early life programming of the immune system?". Proceedings of the Nutrition Society 69 (03): 373–80. doi:10.1017/S0029665110001552. 
42. ^ Jess Halliday (2006-04-13). "Dioxins prompt second UK fish oil withdrawal". http://www.foodproductiondaily.com/news/ng.asp?n=67059-boots-seven-seas-dioxins-fish-oil. Retrieved 2007-02-08. 
43. ^ "Pollutants found in fish oil capsules". BBC News. 2002-04-06. http://news.bbc.co.uk/1/hi/health/1911312.stm. Retrieved 2007-02-08. 
44. ^ International Fish Oil Standards
45. ^ Elisabeth Leamy (2010-03-03). "Lawsuit Raises Fish Oil Supplement Concerns". http://abcnews.go.com/GMA/ConsumerNews/truth-fish-oil-concerns/story?id=9994049. Retrieved 2010-03-05. 
46. ^ "Lawsuit says fish oil supplements contain PCB", San Francisco Chronicle, March 3, 2010
47. ^ Brustad, Magritt; Sandanger, Torkjel Manning; Andersen, Vegard; Lund, Eiliv (2007). "POP exposure from fish liver consumption and risk of cancer?the Norwegian Women and Cancer Study". Journal of Environmental Monitoring 9 (7): 682–6. doi:10.1039/B706302B. PMID 17607388. 

External links

• EPA Fish Consumption Advisories
• International Fish Oil Standards — An organization concerned with the quality of omega-3 products as it relates to the international standards established by the World Health Organization and the Council For Responsible Nutrition for purity and concentration.
• Joyce A. Nettleton, ed. "PUFA Newsletter". http://www.fatsoflife.com. Retrieved February 20, 2006.  Two newsletters, both quarterly, reviewing recent publications in essential fatty acids. One is written for researchers, the second is for consumers. Industry sponsored, academic contributors.
• Clover, Charles (2004). The end of the line: how overfishing is changing the world and what we eat. London: Ebury. ISBN 0-09-189780-7. 
• Oil of Pisces — Summaries of the latest research concerning the health benefits of fish and fish oil