Also see:

PUFA, Fish Oil, and Alzheimers

Fish Oil and Lipid Peroxidation

The Randle Cycle

Women, Estrogen, and Circulating DHA

PUFA – Accumulation & Aging

Medium Chain Fats, Ketones, and Brain Function

PUFA, Development, and Allergy Incidence

Dietary PUFA Reflected in Human Subcutaneous Fat Tissue

Commentary on Type 2 Diabetes

The Great Fish Oil Experiment – Ray Peat

Instead of helping, fish oil drives people towards a heart attack

Too Much of a Good(?) Thing: When Fish Oil Starts Clogging Your Arteries and Fattening Up Your Liver.

“Since the fish oils are commonly studied by comparing the supplemented animals with “control” animals receiving soy oil, corn oil, or safflower oil, which are strongly pro-inflammatory and broadly toxic, it isn’t surprising that their effects usually seem favorable. But when they are compared with saturated fats (as I mentioned in the “Fats and degeneration” newsletter) or with a fat free diet, their effects are seen to be pro-inflammatory and toxic.” -Ray Peat, PhD

The fish oil mega industry as we know it today began as the paint/varnish sector dried up when the petroleum industry took over that market. The fish oil industry had no other place to sell this waste product of fish production so they capitalized on the faulty research done by the Burrs’ in the late 1920s falsely showing essentiality for these fats (it was actually for seed oil fats truthfully but fish oils are the “new” “essential fats”). This misinterpreted research gave the seed and fish oil industry grounds to market these toxic fats as “health foods” for humans.

There is no such thing as “essential fatty acids“; the body doesn’t synthesize “essential” PUFA on its own b/c they are toxic, not because they are essential. One unsaturated fat the body does synthesize from sugar is the protective and anti-inflammatory Omega -9 Mead Acid, which is ironically a marker for “essential fatty acid” deficiency.

Today, the momentum and inertia behind these products is great because of repeated marketing efforts of these industries. The brainwashing is so good that both professionals and laypersons don’t consider taking a look at both the current and historical research about the negative effects of fish oil and other PUFA. We are now at a point of unheard of chronic disease in large part due to our shift away from saturated animal fats/coconut oil and an increase in plant-derived polyunsaturates from vegetables, beans, seed, nuts and fish oils.

Scientific Review of Fish Oils:

Why Fish Oil Fails: A Comprehensive 21st Century Lipids-Based Physiologic Analysis

Cancer Causing:

Cancer Res. 1998 Aug 1;58(15):3312-9.

Dietary omega-3 polyunsaturated fatty acids promote colon carcinoma metastasis in rat liver.

Griffini P, Fehres O, Klieverik L, Vogels IM, Tigchelaar W, Smorenburg SM, Van Noorden CJ.

Nutr Cancer. 1998;30(2):137-43.

Effects of dietary n-3-to-n-6 polyunsaturated fatty acid ratio on mammary carcinogenesis in rats.

Sasaki T, Kobayashi Y, Shimizu J, Wada M, In’nami S, Kanke Y, Takita T.

J Lipid Res. 2005 Jun;46(6):1278-84. Epub 2005 Mar 16.

Role of omega-3 polyunsaturated fatty acids on cyclooxygenase-2 metabolism in brain-metastatic melanoma.

Denkins Y, Kempf D, Ferniz M, Nileshwar S, Marchetti D.

Clin Exp Metastasis. 2000;18(5):371-7.

Promotion of colon cancer metastases in rat liver by fish oil diet is not due to reduced stroma formation.

Klieveri L, Fehres O, Griffini P, Van Noorden CJ, Frederiks WM.

Am. J. Epidemiol. (2011) doi: 10.1093/aje/kwr027

Serum Phospholipid Fatty Acids and Prostate Cancer Risk: Results From the Prostate Cancer Prevention Trial

Theodore M. Brasky, Cathee Till, Emily White, Marian L. Neuhouser, Xiaoling Song, Phyllis Goodman, Ian M. Thompson, Irena B. King, Demetrius Albanes and Alan R. Kristal

Am J Clin Nutr. 2012 Dec;96(6):1354-61. doi: 10.3945/ajcn.112.034157. Epub 2012 Nov 7.

Fatty acid patterns and risk of prostate cancer in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition.

Dahm CC, Gorst-Rasmussen A, Crowe FL, Roswall N, Tjønneland A, Drogan D, Boeing H, Teucher B, Kaaks R, Adarakis G, Zylis D, Trichopoulou A, Fedirko V, Chajes V, Jenab M, Palli D, Pala V, Tumino R, Ricceri F, van Kranen H, Bueno-de-Mesquita HB, Quirós JR, Sánchez MJ, Luján-Barroso L, Larrañaga N, Chirlaque MD, Ardanaz E, Johansson M, Stattin P, Khaw KT, Wareham N, Wark PA, Norat T, Riboli E, Key TJ, Overvad K.

J Nutr. 2003 Nov;133(11):3664-9.

Fish intake is positively associated with breast cancer incidence rate.

Stripp C1, Overvad K, Christensen J, Thomsen BL, Olsen A, Møller S, Tjønneland A.

Immunosuppresion:

Transplantation. 1989 Jul;48(1):98-102.

Enhancement of immunosuppression by substitution of fish oil for olive oil as a vehicle for cyclosporine.

Kelley VE, Kirkman RL, Bastos M, Barrett LV, Strom TB.

Clin Immunol Immunopathol. 1991 Nov;61(2 Pt 1):161-76.

Immunosuppressive effects of fish oil in normal human volunteers: correlation with the in vitro effects of eicosapentanoic acid on human lymphocytes.

Virella G, Fourspring K, Hyman B, Haskill-Stroud R, Long L, Virella I, La Via M, Gross AJ, Lopes-Virella M.

Br J Nutr. 2003 Apr;89(4):523-31.

Influence of very low dietary intake of marine oil on some functional aspects of immune cells in healthy elderly people.

Bechoua S, Dubois M, Véricel E, Chapuy P, Lagarde M, Prigent AF.

Am J Clin Nutr. 2001 Mar;73(3):539-48.

Dietary supplementation with eicosapentaenoic acid, but not with other long-chain n-3 or n-6 polyunsaturated fatty acids, decreases natural killer cell activity in healthy subjects aged >55 y.

Thies F, Nebe-von-Caron G, Powell JR, Yaqoob P, Newsholme EA, Calder PC.

J Nutr. 2001 Jul;131(7):1918-27.

Dietary supplementation with gamma-linolenic acid or fish oil decreases T lymphocyte proliferation in healthy older humans.

Thies F, Nebe-von-Caron G, Powell JR, Yaqoob P, Newsholme EA, Calder PC.

J Cell Physiol. 2010 Nov;225(3):829-36.

Role of calcium and ROS in cell death induced by polyunsaturated fatty acids in murine thymocytes.

Prasad A, Bloom MS, Carpenter DO.

Impairment of mitochondrial function:

Proc Natl Acad Sci U S A. 1990 Nov;87(22):8845-9.

Incorporation of marine lipids into mitochondrial membranes increases susceptibility to damage by calcium and reactive oxygen species: evidence for enhanced activation of phospholipase A2 in mitochondria enriched with n-3 fatty acids.

Malis CD, Weber PC, Leaf A, Bonventre JV.

Int J Biochem Cell Biol. 2012 Sep;44(9):1569-73. Epub 2012 Jun 15.

Mitochondria: Omega-3 in the route of mitochondrial reactive oxygen species.

Al-Gubory KH.

Lipids. 2008 Sep;43(9):813-27. Epub 2008 Jul 10.

Dietary n-3 HUFA affects mitochondrial fatty acid beta-oxidation capacity and susceptibility to oxidative stress in Atlantic salmon.

Kjaer MA, Todorcević M, Torstensen BE, Vegusdal A, Ruyter B.

Increased lipid peroxidation:

Lipids. 1997 May;32(5):535-41.

Lipid peroxidation during n-3 fatty acid and vitamin E supplementation in humans.

Allard JP, Kurian R, Aghdassi E, Muggli R, Royall D.

Atherosclerosis. 2001 Mar;155(1):9-18.

Enhanced level of n-3 fatty acid in membrane phospholipids induces lipid peroxidation in rats fed dietary docosahexaenoic acid oil.

Song JH, Miyazawa T.

J Nutr. 1992 Nov;122(11):2190-5.

Lipid peroxidation products are elevated in fish oil diets even in the presence of added antioxidants.

Gonzalez MJ, Gray JI, Schemmel RA, Dugan L Jr, Welsch CW.

Nutrition. 2004 Feb;20(2):230-4.

Diets rich in saturated and polyunsaturated fatty acids: metabolic shifting and cardiac health.

Diniz YS, Cicogna AC, Padovani CR, Santana LS, Faine LA, Novelli EL.

Int J Biochem Cell Biol. 2012 Sep;44(9):1569-73. Epub 2012 Jun 15.

Mitochondria: Omega-3 in the route of mitochondrial reactive oxygen species.

Al-Gubory KH.

Cardiovascular Disease, Cancer, Mortality, No Benefit or Negative Results:

Cochrane Database Syst Rev. 2004 Oct 18;(4):CD003177.

Omega 3 fatty acids for prevention and treatment of cardiovascular disease.

Hooper L, Thompson RL, Harrison RA, Summerbell CD, Moore H, Worthington HV, Durrington PN, Ness AR, Capps NE, Davey Smith G, Riemersma RA, Ebrahim SB.

Canadian Journal of Cardiology – 14 April 2014 (10.1016/j.cjca.2014.04.007)

“Fishing” for the origins of the “Eskimos and heart disease” story. Facts or wishful thinking? A review

George J. Fodor, Eftyhia Helis, Narges Yazdekhasti, Branislav Vohnout

Mitochondrion. 2011 Jan;11(1):97-103. doi: 10.1016/j.mito.2010.07.014. Epub 2010 Aug 5.

Dietary fatty acids and oxidative stress in the heart mitochondria.

Lemieux H, Bulteau AL, Friguet B, Tardif JC, Blier PU.

BMJ. 2006 Apr 1;332(7544):752-60. Epub 2006 Mar 24.

Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: systematic review.

Hooper L, Thompson RL, Harrison RA, Summerbell CD, Ness AR, Moore HJ, Worthington HV, Durrington PN, Higgins JP, Capps NE, Riemersma RA, Ebrahim SB, Davey Smith G.

Lipids. 2008 Sep;43(9):813-27. Epub 2008 Jul 10.

Dietary n-3 HUFA affects mitochondrial fatty acid beta-oxidation capacity and susceptibility to oxidative stress in Atlantic salmon.

Kjaer MA, Todorcević M, Torstensen BE, Vegusdal A, Ruyter B.

Prog Lipid Res. 1995;34(3):199-217.

Fatty acid composition of adipose tissue in humans. Implications for the dietary fat-serum cholesterol-CHD issue.

Seidelin KN.

Atherosclerosis. 1990 Oct;84(2-3):229-37.

Fish oil produces an atherogenic lipid profile in hypertensive men.

Hughes GS, Ringer TV, Watts KC, DeLoof MJ, Francom SF, Spillers CR.

JAMA. 2012 Sep 12;308(10):1024-33.

Association between omega-3 fatty acid supplementation and risk of major cardiovascular disease events: a systematic review and meta-analysis.

Rizos EC, Ntzani EE, Bika E, Kostapanos MS, Elisaf MS.

Toxic to the liver:

Gastroenterology. 1995 Aug;109(2):547-54.

Dietary saturated fatty acids: a novel treatment for alcoholic liver disease.

Nanji AA, Sadrzadeh SM, Yang EK, Fogt F, Meydani M, Dannenberg AJ.

Hepatology. 1997 Dec;26(6):1538-45.

Dietary saturated fatty acids down-regulate cyclooxygenase-2 and tumor necrosis factor alfa and reverse fibrosis in alcohol-induced liver disease in the rat.

Nanji AA, Zakim D, Rahemtulla A, Daly T, Miao L, Zhao S, Khwaja S, Tahan SR, Dannenberg AJ.

Alcohol. 2004 Aug;34(1):3-8.

Role of fatty liver, dietary fatty acid supplements, and obesity in the progression of alcoholic liver disease: introduction and summary of the symposium.

Purohit V1, Russo D, Coates PM.

J Pharmacol Exp Ther. 2001 Nov;299(2):638-44.

Dietary saturated fatty acids reverse inflammatory and fibrotic changes in rat liver despite continued ethanol administration.

Nanji AA, Jokelainen K, Tipoe GL, Rahemtulla A, Dannenberg AJ.

Am J Physiol Gastrointest Liver Physiol. 2001 Dec;281(6):G1348-56.

Increased severity of alcoholic liver injury in female rats: role of oxidative stress, endotoxin, and chemokines.

Nanji AA, Jokelainen K, Fotouhinia M, Rahemtulla A, Thomas P, Tipoe GL, Su GL, Dannenberg AJ.

J Pharmacol Exp Ther. 2001 Dec;299(3):832-9.

Arginine reverses ethanol-induced inflammatory and fibrotic changes in liver despite continued ethanol administration.

Nanji AA, Jokelainen K, Lau GK, Rahemtulla A, Tipoe GL, Polavarapu R, Lalani EN.



Cognitive Development, Mood, Depression, Quality of Life:

Prostaglandins Leukot Essent Fatty Acids. 1999 May-Jun;60(5-6):393-9.

Does high polyunsaturated free fatty acid level at the feto-maternal interface alter steroid hormone message during pregnancy?

Benassayag C, Rigourd V, Mignot TM, Hassid J, Leroy MJ, Robert B, Civel C, Grangé G, Dallot E, Tanguy J, Nunez EA, Ferré F.

Int Clin Psychopharmacol. 2006 Nov;21(6):319-36.

Fish oil and mental health: the role of n-3 long-chain polyunsaturated fatty acids in cognitive development and neurological disorders.

Assisi A, Banzi R, Buonocore C, Capasso F, Di Muzio V, Michelacci F, Renzo D, Tafuri G, Trotta F, Vitocolonna M, Garattini S.

Neurology. 2008 Aug 5;71(6):430-8.

Effect of fish oil on cognitive performance in older subjects: a randomized, controlled trial.

van de Rest O, Geleijnse JM, Kok FJ, van Staveren WA, Dullemeijer C, Olderikkert MG, Beekman AT, de Groot CP.

Br J Nutr. 2008 Feb;99(2):421-31. Epub 2007 Oct 24.

No effect of n-3 long-chain polyunsaturated fatty acid (EPA and DHA) supplementation on depressed mood and cognitive function: a randomised controlled trial.

Rogers PJ, Appleton KM, Kessler D, Peters TJ, Gunnell D, Hayward RC, Heatherley SV, Christian LM, McNaughton SA, Ness AR.

Br J Nutr. 2012 Apr;107(8):1232-43. Epub 2011 Aug 25.

No effect of 12 weeks’ supplementation with 1 g DHA-rich or EPA-rich fish oil on cognitive function or mood in healthy young adults aged 18-35 years.

Jackson PA, Deary ME, Reay JL, Scholey AB, Kennedy DO.

Am J Clin Nutr. 2008 Sep;88(3):706-13.

Effect of fish-oil supplementation on mental well-being in older subjects: a randomized, double-blind, placebo-controlled trial.

van de Rest O, Geleijnse JM, Kok FJ, van Staveren WA, Hoefnagels WH, Beekman AT, de Groot LC.

Neurotoxicol Teratol. 2010 Mar-Apr;32(2):171-81. Epub 2009 Oct 7.

Excess omega-3 fatty acid consumption by mothers during pregnancy and lactation caused shorter life span and abnormal ABRs in old adult offspring.

Church MW, Jen KL, Anumba JI, Jackson DA, Adams BR, Hotra JW.

J Am Geriatr Soc. 2009 Aug;57(8):1481-6. Epub 2009 Jun 22.

Effect of fish oil supplementation on quality of life in a general population of older Dutch subjects: a randomized, double-blind, placebo-controlled trial.

van de Rest O, Geleijnse JM, Kok FJ, van Staveren WA, Olderikkert MG, Beekman AT, de Groot LC.

J Am Coll Nutr. 2009 Oct;28(5):525-42.

EPA but not DHA appears to be responsible for the efficacy of omega-3 long chain polyunsaturated fatty acid supplementation in depression: evidence from a meta-analysis of randomized controlled trials.

Martins JG.

Glucose Metabolism:

Diabetes. 1989 Oct;38(10):1314-9.

Effects of fish oil supplementation on glucose and lipid metabolism in NIDDM.

Borkman M, Chisholm DJ, Furler SM, Storlien LH, Kraegen EW, Simons LA, Chesterman CN.

Br J Nutr. 2003 Oct;90(4):777-86.

Fish-oil supplementation reduces stimulation of plasma glucose fluxes during exercise in untrained males.

Delarue J, Labarthe F, Cohen R.

Diabetes Care. 1990 Aug;13(8):821-9.

Effects of fish oil supplements in NIDDM subjects. Controlled study.

Hendra TJ, Britton ME, Roper DR, Wagaine-Twabwe D, Jeremy JY, Dandona P, Haines AP, Yudkin JS.

Atherosclerosis. 1991 Mar;87(1):65-73.

A controlled study on the effects of n-3 fatty acids on lipid and glucose metabolism in non-insulin-dependent diabetic patients.

Annuzzi G, Rivellese A, Capaldo B, Di Marino L, Iovine C, Marotta G, Riccardi G.

Eur J Clin Invest. 1992 Oct;22(10):645-50.

Supplementation with n-3 fatty acids reduces triglycerides but increases PAI-1 in non-insulin-dependent diabetes mellitus.

Boberg M, Pollare T, Siegbahn A, Vessby B.

J Intern Med. 1990 Aug;228(2):165-71.

Dietary supplementation with n-3 fatty acids may impair glucose homeostasis in patients with non-insulin-dependent diabetes mellitus.

Vessby B, Boberg M.

Brain Degeneration:

[Isoprostanes and neuroprostanes are inflammatory prostaglandin-like mediators (eicosanoids) formed from omega-3 PUFA fish oil (DHA/EPA).]

J Biol Chem. 1998 May 29;273(22):13605-12.

Formation of isoprostane-like compounds (neuroprostanes) in vivo from docosahexaenoic acid.

Roberts LJ 2nd, Montine TJ, Markesbery WR, Tapper AR, Hardy P, Chemtob S, Dettbarn WD, Morrow JD.

Free Radical Biology and Medicine

Volume 29, Issue 8, 15 October 2000, Pages 714-720

Acrolein, a product of lipid peroxidation, inhibits glucose and glutamate uptake in primary neuronal cultures.

Mark A Lovell, Chengsong Xie, William R Markesbery

Ann Neurol. 1998 Sep;44(3):410-3.

Cerebrospinal fluid F2-isoprostane levels are increased in Alzheimer’s disease.

Montine TJ, Markesbery WR, Morrow JD, Roberts LJ 2nd.

J Neurochem. 1988 Apr;50(4):1185-93.

Induction of intracellular superoxide radical formation by arachidonic acid and by polyunsaturated fatty acids in primary astrocytic cultures.

Chan PH, Chen SF, Yu AC.



Promotes Nitric Oxide and TNF:

J Surg Res. 1994 Jul;57(1):65-8.

Dietary fish oil enhances macrophage production of nitric oxide.

Chaet MS, Garcia VF, Arya G, Ziegler MM.

J Alzheimers Dis. 2003 Aug;5(4):315-22.

Omega-3 fatty acids and risk of cognitive impairment and dementia.

Laurin D, Verreault R, Lindsay J, Dewailly E, Holub BJ.

Brain Swelling:

J Neurochem. 1980 Oct;35(4):1004-7.

Transient formation of superoxide radicals in polyunsaturated fatty acid-induced brain swelling.

Chan PH, Fishman RA.

Science. 1978 Jul 28;201(4353):358-60.

Brain edema: induction in cortical slices by polyunsaturated fatty acids.

Chan PH, Fishman RA.

J Neurochem. 1982 Feb;38(2):525-31.

Phospholipid degradation and cellular edema induced by free radicals in brain cortical slices.

Chan PH, Yurko M, Fishman RA.

Neurotoxicology. 2007 Nov;28(6):1220-9. Epub 2007 Aug 10.

Detrimental effects of post-treatment with fatty acids on brain injury in ischemic rats.

Yang DY, Pan HC, Yen YJ, Wang CC, Chuang YH, Chen SY, Lin SY, Liao SL, Raung SL, Wu CW, Chou MC, Chiang AN, Chen CJ.

Increased Intestinal Permeability:

J Nutr. 2011 Sep;141(9):1635-42. Epub 2011 Jul 20.

Ingestion of (n-3) fatty acids augments basal and platelet activating factor-induced permeability to dextran in the rat mesenteric vascular bed.

Dombrowsky H, Lautenschläger I, Zehethofer N, Lindner B, Schultz H, Uhlig S, Frerichs I, Weiler N.

Lung Inflammation:

Nutrition. 2002 Jul-Aug;18(7-8):647-53.

Dietary fat composition alters pulmonary function in pigs.

Wolfe RR, Martini WZ, Irtun O, Hawkins HK, Barrow RE.

Slow Heart Rate:

Proc Natl Acad Sci U S A. 1994 October 11; 91(21): 9886–9890.

Effects of long-chain polyunsaturated fatty acids on the contraction of neonatal rat cardiac myocytes.

J X Kang and A Leaf