Omega-3 fatty acids are sometimes discussed as a Complementary and Alternative Medicine (CAM) for individuals with autism spectrum disorders (ASD). Lurie Center clinicians summarize current research on magnesium.

Omega-3 fatty acids are building blocks of fats and are commonly found in the oils of fish and certain plants such as flaxseed and hemp. They are “polyunsaturated” fatty acids − they have many double bonds between carbon atoms (C=C) in the carbon chain making up the molecule. Omega-3 fatty acids are often lacking in the American diet but are needed to form “long chain” omega-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These omegas 3’s are important for cell membrane structure and function and regulation of cell signaling. DHA is especially important to the developing brain(1).

The use of fish-derived omega-3 fatty acids to prevent heart attack, stroke and other cardiac causes of death has been supported by some randomized clinical trials and refuted by others. A recent review of the literature found that supplements with omega-3 fatty acids did not decrease the risk of death from all cardiovascular causes(2).

Association of omega-3 fatty acids in ASD

Fish-derived omega-3 fatty acids were first studied in bipolar disorder by Andrew Stoll, MD, at McLean Hospital(3). Dr. Stoll found that patients who took concentrated capsules of omega-3 fatty acids had longer remissions between episodes of mood dysregulation. A recent review has shown omega-3 fatty acids to be useful as add-on therapy in bipolar depression, but not mania(4). Since there is an increased prevalence of bipolar disorder in the extended families of some patients with (ASD)(5), fish oil has been proposed as a treatment for mood stabilization in patients with autism spectrum disorder (ASD).

Other research supports that omega-3 supplements can decrease hyperactivity to a moderate degree in children with ADHD(6). This is another reason for studying these supplements in ASD.

Specific omega-3 fatty acids also play a part in some chemical pathways involved in suppression of inflammation(7). Because inflammation has been documented in the gastrointestinal tract in children with ASD(8), omega-3 supplements have been proposed to decrease the effects of inflammatory pathways in the gut and reduce irritability and pain-related behavior.

Studies have shown abnormal blood levels of various fatty acids in patients with ASD(9,10) It has been suggested that normalization of fatty acid levels in ASD patients would improve brain function and contribute to overall well-being and health. The questions now are:

  1. Whether omega-3 fatty acid supplements normalize fatty acid laboratory values in autism, and
  2. Whether the changes in lab values influence the core symptoms, or any other behavioral parameters in autism.

Studies of omega-3 fatty acids in ASD

There have been small studies of omega-3 fatty acid supplements in children with ASD(11,12) that found tendencies toward decreases in hyperactivity, but the outcomes were not significant, and behaviors were either judged by parent survey or the study showed a large placebo effect. A recent review(13) found that there is not enough scientific evidence to support the effectiveness of omega-3 fatty acids in treating behaviors or core symptoms in ASD. Another review found supplementation did improve hyperactivity (14)

There appears to be no harm in giving omega-3 fatty acids, and larger randomized controlled trials should be done for a definitive answer. Parents may want to consider that instead of using a supplement, omega-3 fatty acids should be derived from the diet (which is more convenient and requires no pills).


  1. Scott BL, Bazan NG 1989 Membrane docosahexaenoate is supplied to the developing brain and retina by the liver. Proc Natl Acad Sci U.S.A. 86: 2903-2907.
    2. Rizos EC, Ntzani EE, Bika E, Kostapanos MS, Elisaf MS. 2012 Association between omega-3 fatty acid supplementation and risk of major cardiovascular disease events. JAMA 308: 1024-1033.
    3. Stoll AL, Severus WE, Freeman MP, Rueter S, Zboyan HA, Diamond E, Cress KK, Marangell LB. 1999 Omega 3 fatty acids in bipolar disorder: a preliminary double-blind, placebo-controlled trial. Arch Gen Psychiatry.  56:407-412.
    4. Sarris J, Mischoulon D, Schweitzer I. 2012 Omega-3 for bipolar disorder: Meta-analyses of use in mania and bipolar depression. J Clin Psychiatry 73: 81-86.
    5. Sullivan PF, Magnusson C, Reichenberg A, Boman M, Dalman C, Davidson M, Fruchter E, Hultman CM, Lundberg M, Långström N, Weiser M, Svensson AC, Lichtenstein P. 2012 Family history of schizophrenia and bipolar disorder are risk factors for autism. Arch Gen Psychiatry 69: 1099-1103.
    6. Bloch MH, Qawasmi A. 2011 Omega-3 fatty acid supplementation for the treatment of children with attention deficit/hyperactivity disorder symptomatology: systematic review and meta-analysis, J Am Acad Child Adolesc Psychiatry 50:991-1000.
    7. Calder PC. 2012 The role of marine omega-3 (n-3) fatty acids in inflammatory processes, atherosclerosis and plaque stability. Mol Nutr Food Res 56: 1073-1080.
    8. Ashwood P, Anthony A, Torrente F, Wakefield AJ 2004 Spontaneous mucosal lymphocyte cytokine profiles in children with autism and gastrointestinal symptoms: mucosal immune activation and reduced counter regulatory interleukin-10. J Clin Immunol 24: 664-673.
    9. Wiest MM, German JB, Harvey DJ, Watkins SM, Hertz-Picciotto I. 2009 Plasma fatty acid profiles in autism: A case control study. Prostaglandins Leukot Essent Fatty Acids 80: 221-227.
    10. Vancassel S, Durand G, Barthelemy C, Lejeune B, Martineau J, Guilloteau D, Andres C, Chalon S. 2001 Plasma fatty acid levels in autistic children. Prostaglandins Leukot Essent Fatty Acids 65:1-7.
    11. Bent S, Bertoglio K, Ashwood, P, Bostrom A, Hendren RL 2011 A pilot randomized controlled trial of omega-3 fatty acids for autism spectrum disorder. J Autism Dev Disord. 41:545-54.
    12. Amminger GP, Berger GE, Schäfer MR, Klier C, Friedrich MH, Feucht M. 2007 Omega-3 fatty acids supplementation in children with autism: a double-blind randomized, placebo-controlled pilot study. Biol Psychiatry. 61:551-553.
    13. James S, Montgomery P, Williams K 2011 Omega-3 fatty acids supplementation for autism spectrum disorders(ASD). Cochrane Database Syst Rev Nov 9;(11):CD007992.
    14. Chang JP, Su KP, Mondelli V, Pariante CM. Omega-3 Polyunsaturated Fatty Acids in Youths with Attention Deficit Hyperactivity Disorder: a Systematic Review and Meta-Analysis of Clinical Trials and Biological Studies. Neuropsychopharmacology. 2018 Feb;43(3):534-545. doi: 10.1038/npp.2017.160. Epub 2017 Jul 25. PMID: 28741625; PMCID: PMC5669464.