Oily fish 691968 224990441 2008-07-11T10:09:26Z Geronimo20 332930 add cat {{fish type topics}} {{distinguish|Oilfish}} '''Oily fish''', '''oil-rich fish''' or '''pelagic fish''' are those [[fish]] which have [[fish oil|oil]]s throughout the [[fillet]] and in the belly cavity around the [[gut]], rather than only in the [[liver]] like [[Whitefish (fisheries term)|white fish]]. Oily fish fillets may contain up to 30 percent oil, although this figure varies both within and between species. Oily fish generally swim in the [[pelagic zone]]s of the oceans. Oily fish are a good source of [[Vitamin]]s [[Vitamin A|A]] and [[Vitamin D|D]] as well as being rich in [[omega 3 fatty acids]]. For this reason the consumption of oily fish has been identified as more beneficial to humans than white fish.{{Who|date=July 2007}} Amongst other benefits, studies suggest that the omega 3 fatty acids in oily fish may help sufferers of [[Clinical depression|depression]], reduce the likelihood of [[Cardiovascular disease|heart disease]] and improve inflammatory conditions such as [[arthritis]].{{Fact|date=July 2007}} ==Research== ===Dementia=== French research published in 2002 in the [[British Medical Journal]] followed 1,674 elderly residents of southern [[France]] for seven years, studying their consumption meat versus seafood and the presence of [[dementia]] symptoms. The conclusion was that people who ate fish at least once a week had a significantly lower risk of being diagnosed with dementia over a seven-year period,<ref>{{cite journal | last = Barberger-Gateau | first = P | coauthors = Letenneur L, Deschamps V, Pérès K, Dartigues JF & Renaud S | year = 2002 | title = Fish, meat, and risk of dementia: cohort study | journal = [[British Medical Journal]] | pmid = 12399342 | url = http://www.bmj.com/cgi/content/short/325/7370/932 | volume = 325 | issue = 7370 | pages = 932–3 | doi = 10.1136/bmj.325.7370.932 | accessdate = 2007-07-26}}</ref> though the study was uncertain if fish consumption protected against dementia, or if dementia prevented the participants from consuming more fish. Individuals with higher education also had a lower risk of dementia and higher consumption of fish, and the relationship between the three factors is uncertain. ===Cardiovascular health=== Consuming oily fish twice per week may also help prevent sudden death due to [[myocardial infarction]] by preventing [[cardiac arrhythmia]].<ref>{{cite journal | last = leaf | first = A. | coauthors = Kang, J.X., Xiao, Y. & Billman, G| title = Clinical prevention of sudden cardiac death by n-3 polyunsaturated fatty acids and mechanism of prevention of arrhythmias by n-3 fish oils | journal = Circulation | volume = 107 | pages = 2646–52 | doi = 10.1161/01.CIR.0000069566.78305.33 | url = http://circ.ahajournals.org/cgi/content/full/107/21/2646 | pmid = 12782616 | accessdate = 2007-07-26| year = 2003}}</ref> The [[eicosapentaenoic acid]] found in fish oils appears to dramatically reduce inflammation through conversion within the body to [[resolvins]], with beneficial effects for the [[cardiovascular system]] and [[arthritis]].<ref>{{cite journal | last = Arita | first = M. | coauthors = Bianchini F, Aliberti J, Sher A, Chiang N, Hong S, Yang R, Petasis NA & Serhan CN | title = Stereochemical assignment, antiinflammatory properties, and receptor for the omega-3 lipid mediator resolvin E1 | journal = [[Journal of Experimental Medicine]] | volume = 201 | issue = 5 | pages = 713–22 | pmid = 15753205 | accessdate = 2007-07-26 | year = 2005 | doi = 10.1084/jem.20042031}}</ref> ==Recommended consumption== {{Unreferenced|date=April 2007}} In [[1994]], the [[United Kingdom|UK]] Committee on Medical Aspects of Food and Nutrition Policy (COMA) recommended that people should eat at least two portions of fish per week, one of which should be oily fish. In 2004 the UK [[Food Standards Agency]] published advice on the recommended minimum and maximum quantities of oily fish to be eaten per week, to balance the beneficial qualities of the Omega 3 fatty acids against the potential dangers of ingesting methylmercury (MeHg). The EPAs Exposure Reference Dose (RfI) for MeHg is 0.1 micrograms per kg body weight per day. The corresponding limit of blood mercury is 5.8 micrograms per liter. The recommendations on maximum consumption of oily fish were up to four portions (1 portion = 140g, or approx 4.9 ounces) a week for men, boys, and women past childbearing age, and up to two portions a week for women of childbearing age, including pregnant and breastfeeding women, and girls. There is no recommended limit on the consumption of [[Whitefish (fisheries term)|white fish]]. The United States Environmental Protection Agency (EPA)and the USDA current guidelines (as of 2007) sets a limit only on consumption of fatty fish with greater than one part per million of methylmercury. Specifically tilefish, king mackrel, shark and swordfish (and some fish caught in local waters). There are limits, however, for nursing/pregnant women and children under the age of 6. This population should completely avoid high MeHg fish (those listed above) and limit consumption of moderate and low MeHg fish to less than or equal to 12oz per week. Albacore tuna should be limited to 6 oz or less per week. (info available at: www.epa.gov/waterscience/fish/states.htm) ==Oils from fish or plants as a source of omega-3 fatty acids== Concerns about [[Mercury (element)#Mercury in fish|contamination]], [[Vegetarianism|diet]] or [[Overfishing|supply]] have led to investigation of plant sources of omega-3 fatty acids, notably [[flaxseed oil|flax]] and [[hempseed oil]]. [[Lactation|Lactating]] women who supplemented their diet with flaxseed oil showed increases in blood and [[breastmilk]] concentration of [[alpha-linolenic acid]] and [[eicosapentaenoic acid]] but no changes to concentrations of [[docosahexaenoic acid]].<ref>{{cite journal | first = C.A. | last = Francois | coauthors = Connor, S.L. Bolewicz, L.C. & Connor, W.E. | title=Supplementing lactating women with flaxseed oil does not increase docosahexaenoic acid in their milk | journal = American Journal of Clinical Nutrition | url=http://www.ajcn.org/cgi/content/full/77/1/226 | accessdate=2007-07-26 | volume = 77 | issue = 1 | pages = 226–233 | year = 2003 | pmid = 12499346 }}</ref> == References == {{reflist}} *Clover, Charles. 2004. ''The End of the Line: How overfishing is changing the world and what we eat''. Ebury Press, London. ISBN 0-09-189780-7 ==External links== *[http://www.ajcn.org/cgi/content/full/78/3/640S Achieving optimal essential fatty acid status in vegetarians: current knowledge and practical implications] (American Journal of Clinical Nutrition) *[http://www.food.gov.uk/news/newsarchive/2004/jun/oilyfishdefinition "What's an oily fish?" from the UK Foods Standards Agency] *[http://www.timesonline.co.uk/article/0,,8126-1158000,00.html "Get smart: eat oily fish on a sensible scale" from the ''Times''] *[http://www.bupa.co.uk/health_information/html/health_news/300604fish.html BUPA article on oily fish] *[http://www.monbiot.com/archives/2006/06/21/not-enough-fish-in-the-sea/ George Monbiot on the environmental problems of sourcing omega-3 from fish] {{fisheries and fishing}} [[Category:Edible fish]] [[Category:Fisheries]] [[Category:Biologically based therapies]] [[ca:Peix blau]] [[de:Fettfische]] [[es:Pescado azul]] [[is:Uppsjávarfiskar]]