Fish oil

For Omegaven, see Fish oil (medical use).

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 certain eicosanoids that are known to reduce inflammation in the body and improve hypertriglyceridemia.[1][2] There has been a great deal of controversy in the 21st century about the role of fish oil in cardiovascular disease, with recent meta-analyses reaching different conclusions about its potential impact.

The fish used as sources do not actually produce omega−3 fatty acids. Instead, the fish accumulate the acids by consuming either microalgae or prey fish that have accumulated omega−3 fatty acids. Fatty predatory fish like sharks, swordfish, 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 may also accumulate toxic substances through biomagnification. For this reason, the United States Environmental Protection Agency recommends limiting consumption (especially for women of childbearing age) of certain (predatory) fish species (e.g., albacore tuna, shark, king mackerel, tilefish and swordfish) due to high levels of the toxic contaminant mercury. Dioxins, like PCBs and chlordane, as well as other chlorinated cyclodiene insecticides are also present.[3] Fish oil is used in aquaculture feed, in particular for feeding farmed salmon.[4]

Marine and freshwater fish oil vary in contents of arachidonic acid, EPA and DHA.[5] The various species range from lean to fatty, and their oil content in the tissues has been shown to vary from 0.7% to 15.5%.[6] They also differ in their effects on organ lipids.[5] Studies have revealed that there is no relation between either 1) total fish intake or 2) estimated omega−3 fatty acid intake from all fish and serum omega−3 fatty acid concentrations.[7] Only fatty fish intake, particularly salmonid, and estimated EPA + DHA intake from fatty fish has been observed to be significantly associated with increase in serum EPA + DHA.[7]

As of 2019, the US Food and Drug Administration (FDA) has approved four fish oil-based prescription drugs, namely Lovaza, Omtryg (both omega-3-acid ethyl esters), Vascepa (ethyl eicosapentaenoic acid), and Epanova (omega-3-carboxylic acids).[8] None of these drugs are actually fish oil; they are all derivatives of acids found in fish oil.

  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. S2CID 41311376.
  2. ^ Cleland, Leslieg; James, Michaelj; Proudman, Susannam (2006). "Fish oil: What the prescriber needs to know". Arthritis Research & Therapy. 8 (1): 679–81. doi:10.1186/ar1876. PMC 1526555. PMID 16542466.
  3. ^ Venus Nandi (9 February 2020). "Best fish to eat". Retrieved 9 February 2020.[permanent dead link‍]
  4. ^ FAO: World Review of Fisheries and Aquaculture 2008: Highlights of Special Studies|date=February 2020 |bot=InternetArchiveBot |fix-attempted=yes }} Rome.
  5. ^ a b Innis, Sheila M.; Rioux, France M.; Auestad, Nancy; Ackman, Robert G. (1995). "Marine and freshwater fish oil varying in arachidonic, eicosapentaenoic and docosahexaenoic acids differ in their effects on organ lipids and fatty acids in growing rats". The Journal of Nutrition. 125 (9): 2286–93. doi:10.1093/jn/125.9.2286. PMID 7666244.
  6. ^ Gruger EH, Nelson RW, Stansby ME (1 October 1964). "Fatty acid composition of oils from 21 species of marine fish, freshwater fish and shellfish". Journal of the American Oil Chemists' Society. 41 (10): 662–67. doi:10.1007/BF02661403. S2CID 84057431.
  7. ^ a b Philibert A, Vanier C, Abdelouahab N, Chan HM, Mergler D (December 2006). "Fish intake and serum fatty acid profiles from freshwater fish". The American Journal of Clinical Nutrition. 84 (6): 1299–307. doi:10.1093/ajcn/84.6.1299. PMID 17158409.
  8. ^ Skulas-Ray, Ann C.; Wilson, Peter W.F.; Harris, William S.; Brinton, Eliot A.; Kris-Etherton, Penny M.; Richter, Chesney K.; Jacobson, Terry A.; Engler, Mary B.; et al. (2019). "Omega-3 Fatty Acids for the Management of Hypertriglyceridemia: A Science Advisory From the American Heart Association". Circulation. 140 (12): e673–e691. doi:10.1161/CIR.0000000000000709. PMID 31422671.