Skip to main content

Long-chain n−3 PUFA: plant v. marine sources

  • Christine M. Williams (a1) and Graham Burdge (a2)

Increasing recognition of the importance of the long-chain n−3 PUFA, EPA and DHA, to cardiovascular health, and in the case of DHA to normal neurological development in the fetus and the newborn, has focused greater attention on the dietary supply of these fatty acids. The reason for low intakes of EPA and DHA in most developed countries (0·1–0·5 g/d) is the low consumption of oily fish, the richest dietary source of these fatty acids. An important question is whether dietary intake of the precursor n−3 fatty acid, α-linolenic acid (αLNA), can provide sufficient amounts of tissue EPA and DHA by conversion through the n−3 PUFA elongation–desaturation pathway. αLNA is present in marked amounts in plant sources, including green leafy vegetables and commonly-consumed oils such as rape-seed and soyabean oils, so that increased intake of this fatty acid would be easier to achieve than via increased fish consumption. However, αLNA-feeding studies and stable-isotope studies using αLNA, which have addressed the question of bioconversion of αLNA to EPA and DHA, have concluded that in adult men conversion to EPA is limited (approximately 8%) and conversion to DHA is extremely low (<0·1%). In women fractional conversion to DHA appears to be greater (9%), which may partly be a result of a lower rate of utilisation of αLNA for β-oxidation in women. However, up-regulation of the conversion of EPA to DHA has also been suggested, as a result of the actions of oestrogen on Δ6-desaturase, and may be of particular importance in maintaining adequate provision of DHA in pregnancy. The effect of oestrogen on DHA concentration in pregnant and lactating women awaits confirmation.

    • Send article to Kindle

      To send this article to your Kindle, first ensure is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the or variations. ‘’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Long-chain n−3 PUFA: plant v. marine sources
      Available formats
      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about sending content to Dropbox.

      Long-chain n−3 PUFA: plant v. marine sources
      Available formats
      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about sending content to Google Drive.

      Long-chain n−3 PUFA: plant v. marine sources
      Available formats
Corresponding author
*Corresponding author: Professor C. M. Williams, fax +44 1189 318703, email
Hide All
Albert CM, Campos H, Stampfer MJ, Ridker PM, Manson JE, Willett WC & Ma J (2002) Blood levels of long-chain n-3 fatty acids and risk of sudden death. New England Journal of Medicine 346 11131118.
Burdge GC & Calder PC (2005) α-Linolenic acid metabolism in adult humans: the effects of gender and age on conversion to longer-chain polyunsaturated fatty acids. European Journal of Lipid Science and Technology 107 426439.
Burdge GC, Finnegan YE, Minihane AM, Williams CM, Wootton SA (2003) Effect of altered dietary n -3 fatty aid intake upon plasma lipid fatty acid composition, conversion of [13 C]α-linolenic acid to longer-chain fatty acids and partitioning towards β-oxidation in older men. British Journal of Nutrition 90 311321.
Burdge GC, Jones AE, Wootton SA (2002) Eicosapentaenoic and docosapentaenoic acids are the principal products of α-linolenic acid metabolism in young men. British Journal of Nutrition 88 355363.
Burdge GC & Wootton SA (2002) Conversion of α-linolenic acid to eicosapentaenoic, docosapentaenoic and docosahexaenoic acids in young women. British Journal of Nutrition 88 411420.
Burr ML, Ashfield-Watt PA, Dunstan FD, Fehily AM, Breay P, Ashton T, Zotos PC, Haboubi NA & Elwood PC (2003) Lack of benefit of dietary advice to men with angina: results of a controlled trial. European Journal of Clinical Nutrition 57 193200.
Burr ML, Fehily AM, Gilbert JF, Rogers S, Holliday RM, Sweetman PM, Elwood PC, Deadman NM (1989) Effects of changes in fat, fish, and fibre intakes on death and myocardial reinfarction: direct and reinfarction trial (DART). Lancet ii 757761.
Calder PC (2004) n-3 Fatty acids and cardiovascular disease: evidence explained and mechanisms explored. Clinical Science (London) 107 111.
Carnielli VP, Wattimena DJ, Luijendijk IH, Boerlage A, Degenhart HJ, Sauer PJ (1996) The very-low-birth-weight premature infant is capable of synthesizing arachidonic and docosahexaenoic acid from linolenic and linolenic acid. Pediatric Research 40 169174.
Clandinin MT, Chappell JE, Hein T, Swyer PR, Chance GW (1981) Fatty acid accretion in fetal and neonatal liver: implications for fatty acid requirements. Early Human Development 5 714.
Clandinin MT, Chappell JE, Leong S, Heim T, Swyer PR, Chance GW (1980) Intrauterine fatty acid accretion rates in human brain: implications for fatty acid requirements. Early Human Development 4 121129.
Cunnane SC, Hamadeh MJ, Liede AC, Thompson LU, Wolever TM & Jenkins DJ (1995) Nutritional attributes of traditional flaxseed in healthy young adults. American Journal of Nutrition 61 6268.
de Gomez Dumm IN, Brenner RR (1975) Oxidative desaturation of alpha-linoleic, linoleic, and stearic acids by human liver microsomes. Lipids 10 315317.
Emken EA (2001) Stable isotope approaches, applications and issues related to polyunsaturated fatty acid metabolism studies. Lipids 36 965973.
Emken EA, Adlof RO, Duval SM & Nelson GJ (1999) Effect of dietary docosahexaenoic acid on desaturation and uptake in vivo of isotope-labeled oleic, linoleic and linolenic acids by male subjects. Lipids 34 785798.
Emken EA, Adlof RO, Gulley RM (1994) Dietary linoleic acid influences desaturation and acylation of deuterium-labeled linoleic and linolenic acids in young adult males. Biochimica et Biophysica Acta 1213 277288.
Finnegan YE, Minihane AM, Leigh-Firbank EC, Kew S, Meijer GW, Muggli R, Calder PC, Williams CM (2003) Plant- and marine-derived n-3 polyunsaturated fatty acids have differential effects on fasting and postprandial blood lipid concentrations and on the susceptibility of LDL to oxidative modification in moderately hyperlipidemic subjects. American Journal of Nutrition 77 783795.
Francois CA, Connor SL, Bolewicz LC & Connor WE (2003) Supplementing lactating women with flaxseed oil does not increase docosahexaenoic acid in their milk. American Journal of Nutrition 77 226233.
Giltay EJ, Gooren LJ, Toorians AW, Katan MB, Zock PL (2004) Docosahexaenoic acid concentrations are higher in women than in men because of estrogenic effects. American Journal of Nutrition 80 11671174.
GISSI-Prevenzione Investigators (1999) Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Gruppo Italiano per lo Studio della Sopravvienza nell'Infarto miocardico. Lancet 354 447455.
Goyens PL, Spilker ME, Zock PL, Katan MB, Mensink RP (2005) Compartmental modeling to quantify alpha-linolenic acid conversion after longer term intake of multiple tracer boluses. Journal of Lipid Research 46 14741483.
Gregersen MI & Rawson RA (1959) Blood volume. Physiological Reviews 39 307342.
Haggarty P (2004) Effect of placental function on fatty acid requirements during pregnancy. European Journal of Clinical Nutrition 58 15591570.
Helland IB, Saugstad DO, Smith L, Saarem K, Solvoll K, Ganes T & Drevon CA (2001) Similar effects on infants of n-3 and n-6 fatty acids supplementation to pregnant and lactating women. Pediatrics 108 E82
Henderson L, Gregory J, Irving K & Swan G (2004) National Diet and Nutrition Survey: Adults Aged 19 to 64 Years. vol. 2: Energy, Protein, Fat and Carbohydrate Intake. London: The Stationery Office.
Hussein N, Ah-Sing E, Wilkinson P, Leach C, Griffin BA, Millward DJ (2005) Relative rates of long chain conversion of 13C linoleic and α-linolenic acid in response to marked changes in their dietary intake in male adults. Journal of Lipid Research 46 269280.
James MJ, Ursin VM, Cleland LG (2003) Metabolism of stearidonic acid in human subjects: comparison with the metabolism of other n-3 fatty acids. American Journal of Nutrition 77 11401145.
Jeffrey BG, Weisinger HS, Neuringer M & Mitchell DC (2001) The role of docosahexaenoic acid in retinal function. Lipids 36 859871.
Jensen CL, Maude M, Anderson RE, Heird WC (2000) Effect of docoshexaenoic acid supplementation of lactating women on the fatty acid composition of breast milk lipids and maternal and infant plasma phospholipids. American Journal of Nutrition 71 292S299S.
Jorgensen MH, Hernell O, Hughes E & Michaelsen KF (2001) Is there a relation between docosahexaenoic acid concentration in mother's milk and visual development in term infants. Journal of Pediatric Gasteroenterology and Nutrition 32 293296.
Li D, Sinclair A, Wilson A, Nakkote S, Kelly F, Abedin L, Mann N & Turner A (1999) Effect of dietary alpha-linolenic acid on thrombotic risk factors in vegetarian men. American Journal of Nutrition 69 872882.
Makrides M & Gibson RA (2000) Long-chain polyunsaturated fatty acid requirements during pregnancy and lactation. American Journal of Nutrition 71 307311.
Malcolm CA, McCulloch DL, Montgomery C, Shepherd A & Weaver LT (2003) Maternal docosahexaenoic acid supplementation during pregnancy and visual evoked potential development in term infants: a double blind, prospective, randomized trial. Archives of Disease in Childhood 88 F383F390.
Mantzioris E, James MJ, Gibson RA & Cleland LG (1994) Dietary substitution with an alpha-linolenic acid-rich vegetable oil increases eicosapentaenoic acid concentrations in tissues. American Journal of Nutrition 59 13041309.
Mitchell DC, Niu SL, Litman BJ (2003) Enhancement of G protein-coupled signaling by DHA phospholipids. Lipids 38 437443.
Olsen SF, Hansen HS, Secher NJ, Jenson B, Sandstrom B (1995) Gestation length and birth weight in relation to intake of marine n -3 fatty acids. British Journal of Nutrition 73 397404.
Olsen SF & Secher NJ (2002) Low consumption of seafood in early pregnancy as a risk factor for preterm delivery: prospective cohort study. British Medical Journal 324 447
Olsen SF, Secher NJ, Tabor A, Weber T, Walker JJ & Gluud C (2000) Randomized clinical trials of fish oil supplementation in high risk pregnancies. Fish Oil Trials In Pregnancy (FOTIP) Team. BJOG: an International Journal of Obstetrics and Gynaecology 107 382395.
Olsen SF, Sorensen JD, Secher NJ, Hedegaard M, Henriksen TB, Hansen HS & Grant A (1992) Randomized controlled trial of effect of fish-oil supplementation on pregnancy duration. Lancet 339 10031007.
Ottosson UB, Lagrelius A, Rosing U, von Schoultz B (1984) Relative fatty acids composition of lecithin during postmenopausal replacement therapy – a comparison between ethinyl estradiol and estradiol valerate. Gynecologic and Obstetric Investigation 18 296302.
Pawlosky RJ, Hibbeln JR, Lin Y, Goodson S, Riggs P, Sebring N, Brown GL & Salem N (2003 a) Effects of beef- and fish-based diets on the kinetics of n-3 fatty acid metabolism in human subjects. American Journal of Clinical Nutrition 77 565572.
Pawlosky R, Hibbeln J, Lin Y & Salem N (2003 b) n-3 fatty acid metabolism in women. British Journal of Nutrition 90 993994.
Pawlosky RJ, Hibbeln JR, Novotny JA & Salem N (2001) Physiological compartmental analysis of α-linolenic acid metabolism in adult humans. Journal of Lipid Research 42 12571265.
Poisson J-P, Dupuy R-P, Sarda P, Descomps B, Narce M, Rieu D, Crastes de Paulet A (1993) Evidence that liver microsomes of human neonates desaturate essential fatty acids. Biochimica et Biophysica Acta 1167 109113.
Postle AD, Al MD, Burdge GC & Hornstra G (1995) The composition of individual molecular species of plasma phosphatidylcholine in human pregnancy. Early Human Development 43 4758.
Salem N, Powlosky R, Wegher B & Hibbeln J (1999) In vivo conversion of linolenic acid to arachidonic acid in human adults. Prostaglandins, Leukotrienes, and Essential Fatty Acids 60 407410.
Salem N, Wegher B, Mena P & Uauy R (1996) Arachidonic and docosahexaenoic acids are biosynthesized from their 18-carbon precursors in human infants. Proceedings of the National Academy of Sciences USA 93 4954.
Sanders TA & Younger KM (1981) The effect of dietary supplements of omega 3 polyunsaturated fatty acids on the fatty acid composition of platelets and plasma choline phosphoglycerides. British Journal of Nutrition 45 613616.
Scientific Advisory Committee on Nutrition (2004) Advice on Fish Consumption: Benefits and Risks. SACN/COT Report. London: The Stationery Office.
Singh RB, Niaz MA, Harma JP, Kumar R, Rastogi V & Moshiri M (1997) Randomized, double-blind, placebo-controlled trial of fish oil and mustard oil in patients with suspected acute myocardial infarction: the Indian experiment of infarct survival – 4. Cardiovascular Drugs and Therapy 11 485491.
Siscovick DS, Raghunathan TE, King I, Weinmann S, Wicklund KG, Albright J et al. (1995) Dietary intake and cell membrane levels of long-chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest. Journal of American Medical Association 274 13631367.
Smuts CM, Huang M, Mundy D, Plasse T, Major S & Carlson SE (2003) A randomized trial of docosahexaenoic acid supplementation during the third trimester of pregnancy. Obstetrics and Gynecology 101 469479.
Sprecher H (2002) The roles of anabolic and catabolic reactions in the synthesis and recycling of polyunsaturated fatty acids. Prostaglandins, Leukotrienes, and Essential Fatty Acids 67 7983.
Vermunt SHF, Mensink RP, Simonis AMG & Hornstra G (2000) Effects of dietary α-linolenic acid on the conversion and oxidation of [13C]-α-linolenic acid. Lipids 35 137142.
Wallace FA, Miles EA, Calder PC (2003) Comparison of the effects of linseed oil and different doses of fish oil on mononuclear cell function in healthy human subjects. British Journal of Nutrition 89 679689.
Williams C, Birch EE, Emmett PM & Northstone K (2001) Avon Longitudinal Study of Pregnancy and Childhood Study Team. Stereoacuity at age 3·5y in children born full-term is associated with prenatal and postnatal dietary factors: a report from a population-based cohort study. American Journal of Nutrition 73 316322.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Proceedings of the Nutrition Society
  • ISSN: 0029-6651
  • EISSN: 1475-2719
  • URL: /core/journals/proceedings-of-the-nutrition-society
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Altmetric attention score

Full text views

Total number of HTML views: 2
Total number of PDF views: 584 *
Loading metrics...

Abstract views

Total abstract views: 950 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 21st January 2018. This data will be updated every 24 hours.