Editing Essential fatty acid (section)

==Food sources==

Some of the food sources of ω−3 and ω−6 fatty acids are [[fish]] and [[shellfish]], seaweed oil, [[flax]]seed (linseed) and [[flaxseed oil]], [[hemp seed]], [[olive oil]], [[soybean oil|soya oil]], [[canola oil|canola (rapeseed) oil]], [[salvia hispanica|chia seeds]], [[pumpkin seed]]s, [[sunflower seeds]], [[leafy vegetable]]s, and [[walnut]]s.

Essential fatty acids play a part in many [[metabolism|metabolic processes]], and there is evidence to suggest that low levels of essential fatty acids, or the wrong balance of types among the essential fatty acids, may be a factor in a number of illnesses, including [[osteoporosis]].<ref>{{cite journal |vauthors=Kruger MC, Horrobin DF |title=Calcium metabolism, osteoporosis and essential fatty acids: a review |journal=Progress in Lipid Research |volume=36 |issue=2–3 |pages=131–51 |date=September 1997 |pmid=9624425 |doi=10.1016/S0163-7827(97)00007-6}}</ref>

Fish is the main source of the longer omega−3 fats; eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), though they initially acquire these fats through the consumption of algae and seaweed. Some plant-based foods contain omega−3 in the form of alpha-linolenic acid (ALA), which appears to have a modest benefit for cardiovascular health.<ref>{{cite journal |vauthors=Pan A, Chen M, Chowdhury R |title=α-Linolenic acid and risk of cardiovascular disease: a systematic review and meta-analysis |journal=Am. J. Clin. Nutr. |volume=96 |issue=6 |pages=1262–73 |date=December 2012  |pmid=23076616 |pmc=3497923 |doi=10.3945/ajcn.112.044040 |type=Systematic review|display-authors=etal}}</ref> The human body can (and in case of a purely vegetarian diet often must unless certain [[algae]] or supplements derived from them are consumed) convert ALA to EPA and subsequently DHA. The conversion of ALA to DHA is sufficient in the adult and additional DHA is not required in the diet.<ref name=":0">{{Cite journal |last1=Domenichiello |first1=Anthony F. |last2=Kitson |first2=Alex P. |last3=Bazinet |first3=Richard P. |date=July 2015 |title=Is docosahexaenoic acid synthesis from α-linolenic acid sufficient to supply the adult brain? |url=https://linkinghub.elsevier.com/retrieve/pii/S0163782715000223 |journal=Progress in Lipid Research |language=en |volume=59 |pages=54–66 |doi=10.1016/j.plipres.2015.04.002|pmid=25920364 |doi-access=free }}</ref> In the infant, the case is less clear; preformed DHA may be required in breastmilk or formula for adequate development, as DHA supplementation in formula was found to improve cognitive development up to one year of age.<ref name=":0" /> The effects of DHA supplementation in early childhood after one year are unclear.<ref name=":0" />

The ''IUPAC Lipid Handbook'' provides a very large and detailed listing of fat contents of animal and vegetable fats, including ω−3 and −6 oils.<ref>{{cite web|url=http://www.iupac.org/publications/pac/2001/pdf/7304x0685.pdf|title=IUPAC Lipid Handbook|website=iupac.org|url-status=live|archive-url=https://web.archive.org/web/20060212173746/http://www.iupac.org/publications/pac/2001/pdf/7304x0685.pdf|archive-date=2006-02-12}}</ref> The [[National Institutes of Health]]'s EFA Education group publishes ''Essential Fats in Food Oils''.<ref>{{cite web|url=http://efaeducation.org/Bal_pdfs/FatsOils.pdf|title=Essential Fats in Food Oils|website=efaeducation.org|url-status=live|archive-url=https://web.archive.org/web/20141210062034/http://efaeducation.org/Bal_pdfs/FatsOils.pdf|archive-date=2014-12-10}}</ref> This lists 40 common oils, more tightly focused on EFAs and sorted by n−6:3 ratio. ''Vegetable Lipids as Components of Functional Food'' lists notable vegetable sources of EFAs as well as commentary and an overview of the biosynthetic pathways involved.<ref>[http://publib.upol.cz/~obd/fulltext/Biomedic146-2/LF11_2002-1.pdf Vegetable Lipids as Components of Functional Food] {{webarchive|url=https://web.archive.org/web/20060320003053/http://publib.upol.cz/~obd/fulltext/Biomedic146-2/LF11_2002-1.pdf |date=2006-03-20 }}, Stuchlik and Zak</ref> However, these sources are not in perfect agreement. EFA content of vegetable sources varies with cultivation conditions. Animal sources vary widely, both with the animal's feed and that the EFA makeup varies markedly with fats from different body parts.