View source for Omega−6 fatty acid

{{Short description|Fatty acids where the sixth bond is double}}
<!--To be strictly correct the term is omega−3, with a minus sign or en dash. Be careful with global replacement, as omega[hyphen]3 is used in some URLs; links to sources will break if they are changed.-->
{{For|the 1920s French automobile|Oméga-Six}}
{{Distinguish|Omega−3 fatty acid|Trans fatty acid}}
{{Fats}}
[[Image:Oenothera biennis 20050825 962.jpg|thumb|200px|The evening primrose flower (''O. biennis'') produces an oil containing a high content of [[γ-linolenic acid]], a type of omega−6 fatty acid.]]
'''Omega−6 fatty acids''' (also referred to as '''ω−6 fatty acids''' or '''''n''−6 fatty acids''') are a family of [[polyunsaturated fatty acids]] (PUFA) that share a final carbon-carbon [[double bond#Bond order|double bond]] in the [[Fatty acid#Nomenclature|''n''−6]] position, that is, the sixth bond, counting from the [[methyl]] end.<ref>{{Cite book |last=Chow |first=Ching Kuang |title=Fatty Acids in Foods and Their Health Implications |publisher=Routledge Publishing |year=2001 |location=New York |oclc=25508943}}{{page needed|date=July 2013}}</ref> Health and medical organizations recommend intake of omega−6 fatty acids as part of [[Healthy diet|healthful dietary patterns]].<ref name="AMA">{{cite journal |last1=Harris |first1=WS |last2=Mozaffarian |first2=D |last3=Rimm |first3=E |last4=Kris-Etherton |first4=P |last5=Rudel |first5=LL |last6=Appel |first6=LJ |last7=Engler |first7=MM |last8=Engler |first8=MB |last9=Sacks |first9=F |title=Omega-6 fatty acids and risk for cardiovascular disease: a science advisory from the American Heart Association Nutrition Subcommittee of the Council on Nutrition, Physical Activity, and Metabolism; Council on Cardiovascular Nursing; and Council on Epidemiology and Prevention |journal=Circulation |volume=119 |issue=6 |pages=902–7 |year=2009 |pmid=19171857 |doi=10.1161/CIRCULATIONAHA.108.191627 |doi-access=free}}</ref><ref>{{cite journal |vauthors=Petersen KS, Maki KC, Calder PC, Belury MA, Messina M, Kirkpatrick CF, Harris WS|date=2024|title=Perspective on the health effects of unsaturated fatty acids and commonly consumed plant oils high in unsaturated fat|journal=British Journal of Nutrition| url=https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/perspective-on-the-health-effects-of-unsaturated-fatty-acids-and-commonly-consumed-plant-oils-high-in-unsaturated-fat/54F76A9404C9D1B192EB59DD8E6DC3F3| volume=132 |issue=8 |pages=1039-1050 |doi=10.1017/S0007114524002459 |doi-access=free |pmc=11600290 |pmid=39475012}}</ref><ref name="Nordic">{{cite journal|author=Retterstøl K, Rosqvist F.|year=2024|title=Fat and fatty acids – a scoping review for Nordic Nutrition Recommendations 2023|journal=Food Nutr Res|url=https://foodandnutritionresearch.net/index.php/fnr/article/view/9980|volume=68|issue=|pages=|doi=10.29219/fnr.v68.9980|pmid=38327998|pmc=10845901 |hdl=10852/114875|hdl-access=free}}</ref>

== Health effects ==

The [[American Heart Association]] "supports an omega-6 PUFA intake of at least 5% to 10% of energy in the context of other AHA lifestyle and dietary recommendations. To reduce omega−6 PUFA intakes from their current levels would be more likely to increase than to decrease risk for coronary heart disease."<ref name="AMA"/>

A 2018 review found that an increased intake of omega−6 fatty acids reduces total serum cholesterol and may reduce [[myocardial infarction]] (heart attack), but found no significant change in [[Low-density lipoprotein|LDL cholesterol]] and [[triglyceride]]s.<ref>{{cite journal |vauthors=Hooper L, Al-Khudairy L, Abdelhamid AS, Rees K, Brainard JS, Brown TJ, Ajabnoor SM, O'Brien AT, Winstanley LE, Donaldson DH, Song F, Deane KH |year=2018 |title=Omega-6 fats for the primary and secondary prevention of cardiovascular disease |journal=Cochrane Database of Systematic Reviews |volume=2018 |issue=11 |at=CD011094 |doi=10.1002/14651858.CD011094.pub4 |pmid=30488422 |pmc=6516799 }}</ref> A 2021 review found that omega−6 supplements do not affect the risk of [[Cardiovascular disease|CVD]] morbidity and mortality.<ref>{{cite journal |vauthors=Mazidi M, Shekoohi N, Katsiki N, Banach M |year=2021 |title=Omega-6 fatty acids and the risk of cardiovascular disease: insights from a systematic review and meta-analysis of randomized controlled trials and a Mendelian randomization study |journal=Archives of Medical Science |volume=18 |issue=2 |pages=466–479 |doi=10.5114/aoms/136070 |pmid=35316920|pmc=8924827 }}</ref>

A 2023 review found that omega−6 polyunsaturated fatty acids are associated with lower risk of high [[blood pressure]].<ref>{{cite journal|author=Hajihashemi P, Feizi A, Heidari Z, Haghighatdoost F.|year=2023|title=Association of omega-6 polyunsaturated fatty acids with blood pressure: A systematic review and meta-analysis of observational studies|journal=Critical Reviews in Food Science and Nutrition|url=https://www.tandfonline.com/doi/abs/10.1080/10408398.2021.1973364|volume=63|issue=14|pages=2247–2259| doi=10.1080/10408398.2021.1973364|pmid=36939291|url-access=subscription}}</ref> Omega−6 fatty acids are not associated with [[atrial fibrillation]].<ref>{{cite journal|author=Garg PK, Guan W, Nomura S, Weir NL, Tintle N, Virtanen JK, Hirakawa Y, Qian F, Sun Q, Rimm E, Lemaitre RN, Jensen PN, Heckbert SR, Imamura F, Steur M, Leander K, Laguzzi F, Voortman T, Ninomiya T, Mozaffarian D, Harris WS, Siscovick DS, Tsai MY|year=2023|title=Fatty Acids and Outcomes Research Consortium (FORCE). n-6 fatty acid biomarkers and incident atrial fibrillation: an individual participant-level pooled analysis of 11 international prospective studies.|journal=The American Journal of Clinical Nutrition|volume=118|issue=5|pages=921–929|doi=10.1016/j.ajcnut.2023.09.008|pmid= 37769813|doi-access=free}}</ref>

A review and meta-analysis of observational studies by the [[World Health Organization]] (WHO) found that higher intakes of omega−6 are associated with a 9% reduced risk of [[all-cause mortality]] and a 31% increased risk of postmenopausal breast cancer.<ref>{{Cite book |last=DE SOUZA |first=Russell |title=Polyunsaturated Fatty Acids Intake and Risk of All-Cause Mortality, Cardiovascular Disease, Breast Cancer, Mental Health, and Type 2 Diabetes: A Systematic Review and Meta-Analysis of Prospective Cohort Studies |date=2022 |publisher=World Health Organization |others=Michael A. ZULYNIAK, Mina KAZEMI, Rahim ALI, Rachel BIERBRIER, Natalie WILLIAMS, Rosain STENNETT, Laura BANFIELD |isbn=978-92-4-006164-4 |edition=1st |location=Geneva |url=https://iris.who.int/bitstream/handle/10665/365671/9789240061644-eng.pdf}}</ref> The increased risk of breast cancer has not been confirmed in randomized controlled trials.<ref>{{cite journal|author=Hanson S, Thorpe G, Winstanley L, Abdelhamid AS, Hooper L|year=2020|title=Omega-3, omega-6 and total dietary polyunsaturated fat on cancer incidence: systematic review and meta-analysis of randomised trials|journal=Br J Cancer|volume=122|issue=8|pages=1260–1270|doi=10.1038/s41416-020-0761-6|pmid=32114592 |pmc=7156752}}</ref>

A scoping review for Nordic Nutrition Recommendations 2023 found that partial replacement of [[saturated fatty acid]] with omega−6 fatty acid decreases risk of cardiovascular disease and improves the blood lipid profile.<ref name="Nordic"/> A 2025 meta-analysis of 150 cohorts and meta-regression found that higher dietary intake and circulating levels of omega−6 fatty acids are associated with a lowered risk of cardiovascular disease, cancer and all-cause mortality.<ref>{{cite journal |vauthors=Sadeghi, R, Norouzzadeh, M, HasanRashedi, M|date=2025 |title=Dietary and circulating omega-6 fatty acids and their impact on cardiovascular disease, cancer risk, and mortality: a global meta-analysis of 150 cohorts and meta-regression |journal=Journal of Translational Medicine |volume=23 |issue= |pages=314 |doi=10.1186/s12967-025-06336-2 |doi-access=free |pmc=11899657 |pmid=}}</ref>

==Dietary sources==
Dietary sources of omega−6 fatty acids include:<ref name="NIH omega 6">{{cite web
  | title = Food sources of total omega 6 fatty acids
  | url = http://riskfactor.cancer.gov/diet/foodsources/fatty_acids/table2.html
  | access-date = 2011-09-04
  | archive-url = https://web.archive.org/web/20111007012342/http://riskfactor.cancer.gov/diet/foodsources/fatty_acids/table2.html
  | archive-date = 2011-10-07
  | url-status = dead
  }}</ref>
* [[poultry]]
* [[egg (food)|egg]]s
* [[nut (fruit)|nuts]]
* [[sesame|hulled sesame seeds]]
* [[cereal]]s
* [[durum wheat]]
* [[whole-grain]] breads
* [[pumpkin seeds]]
* [[hemp seeds]]

=== Vegetable oils ===
[[Vegetable oil]]s are a major source of omega−6 [[linoleic acid]]. Worldwide, more than 100 million [[metric ton]]s of vegetable oils are extracted annually from [[palm oil|palm fruits]], [[soybean oil|soybean seeds]], [[grape seed oil|grape seeds]], and [[sunflower oil|sunflower seeds]], providing more than 32 million metric tons of omega−6 linoleic acid and 4 million metric tons of omega−3 [[alpha-linolenic acid]].<ref>{{cite journal |last1=Gunstone |first1=Frank |date=December 2007 |title=Market update: Palm oil |journal=International News on Fats, Oils and Related Materials |volume=18 |issue=12 |pages=835–36 |url=http://www.highbeam.com/doc/1P3-1421893231.html|archive-url=https://web.archive.org/web/20130403202146/http://www.highbeam.com/doc/1P3-1421893231.html|url-status=dead|archive-date=2013-04-03}}</ref><ref name="USDAOilSeeds2009-01">{{Cite journal
| journal=Oilseeds: World Market and Trade
| issue=January 2009
| title=Soybean Oil Prices Suddenly Diverge from Energy Market
| url=http://www.fas.usda.gov/oilseeds/circular/2009/January/Oilseedsfull0109.pdf
| id=FOP 1-09
| date=2009-01-12
| publisher=[[USDA]]
| access-date=2019-08-09
| archive-url=https://web.archive.org/web/20130309135414/http://@fas.usda.gov/oilseeds/circular/2009/January/Oilseedsfull0109.pdf
| archive-date=2013-03-09
| url-status=dead
}}, Table 03: Major Vegetable Oils: World Supply and Distribution at [http://www.fas.usda.gov/oilseeds/circular/Current.asp Oilseeds: World Markets and Trade Monthly Circular] {{Webarchive|url=https://web.archive.org/web/20101018161150/http://www.fas.usda.gov/oilseeds/circular/Current.asp |date=2010-10-18 }}</ref>

{{Vegetable oils comparison}}
[[File:Comparison of dietary fat composition.svg|thumb|Comparison of dietary fat composition from a 1995 study.]]

== List of omega−6 fatty acids ==
[[Image:LAnumbering.png|thumb|upright=1.8|none|The [[chemical structure]] of [[linoleic acid]], a common omega−6 fatty acid found in many [[Nut (fruit)|nuts]], [[seeds]], and [[vegetable oil]]s.]]
{| class="wikitable"
! Common name
! Lipid name
! Chemical name
|-
| [[Linoleic acid]] (LA)
| 18:2 (''n''−6)
| ''all-cis''-9,12-octadecadienoic acid
|-
| [[Gamma-linolenic acid]] (GLA)
| 18:3 (''n''−6)
| ''all-cis''-6,9,12-octadecatrienoic acid
|-
| [[Calendic acid]]
| 18:3 (''n''−6)
| 8E,10E,12Z-octadecatrienoic acid
|-
| [[Eicosadienoic acid]]
| 20:2 (''n''−6)
| ''all-cis''-11,14-eicosadienoic acid
|-
| [[Dihomo-gamma-linolenic acid]] (DGLA)
| 20:3 (''n''−6)
| ''all-cis''-8,11,14-eicosatrienoic acid
|-
| [[Arachidonic acid]] (AA, ARA)
| 20:4 (''n''−6)
| ''all-cis''-5,8,11,14-eicosatetraenoic acid
|-
| [[Docosadienoic acid]]
| 22:2 (''n''−6)
| ''all-cis''-13,16-docosadienoic acid
|-
| [[Docosatetraenoic acid|Adrenic acid]]
| 22:4 (''n''−6)
| ''all-cis''-7,10,13,16-docosatetraenoic acid
|-
| [[Osbond acid]]
| 22:5 (''n''−6)
| ''all-cis''-4,7,10,13,16-docosapentaenoic acid
|-
|  [[Tetracosatetraenoic acid]]
| 24:4 (''n''−6)
|''all-cis''-9,12,15,18-tetracosatetraenoic acid
|-
| [[Tetracosapentaenoic acid]]
| 24:5 (''n''−6)
| ''all-cis''-6,9,12,15,18-tetracosapentaenoic acid
|}

The melting point of the fatty acids increases as the number of carbons in the chain increases.<ref>{{Cite web |date=2020-04-30 |title=Biochemical Properties of Lipids |url=https://themedicalbiochemistrypage.org/biochemistry-of-lipids/ |access-date=2022-05-11 |website=The Medical Biochemistry Page |language=en-US}}</ref>

==See also==
{{Portal|Biology|Medicine}}
<!-- Please keep entries in alphabetical order & add a short description [[WP:SEEALSO]] -->
{{div col|colwidth=20em|small=yes}}
* [[Cattle feeding]]
* [[Essential fatty acid interactions]]
* [[Essential nutrients]]
* [[Inflammation]]
* [[alpha-Linolenic acid|Linolenic acid]]
* [[Lipid peroxidation]]
* [[Olive oil regulation and adulteration]]
* [[Omega-3 fatty acid|Omega−3 fatty acid]]
* [[Omega-7 fatty acid|Omega−7 fatty acid]]
* [[Omega-9 fatty acid|Omega−9 fatty acid]]
* [[Ratio of fatty acids in different foods]]
* [[Wheat germ oil]]
{{div col end}}
<!-- please keep entries in alphabetical order -->

== References ==
{{Reflist}}

== Further reading ==
*{{cite book
 |isbn=978-0-920470-38-1
 |title=Fats That Heal, Fats That Kill
 |first=Udo
 |last=Erasmus
 |edition=3rd
 |location=Burnaby (BC)
 |publisher=Alive Books |year=1993}}

{{Lipids}}
{{Fatty acids}}<!--
{{Prostanoidergics}}
{{Leukotrienergics}}
{{Cannabinoidergics}}-->

{{Authority control}}

{{DEFAULTSORT:Omega-6 Fatty Acid}}
[[Category:Fatty acids]]
[[Category:Essential nutrients]]
[[Category:Treatment of bipolar disorder]]
[[Category:Alkenoic acids]]

[[de:Omega-n-Fettsäuren#Omega-6-Fettsäuren]]