By Jennifer Copley (Last Updated 30 March 2012)
Essential fatty acids (EFAs), which are critical for various biochemical processes, can’t be made by the body and so must be obtained via food or supplements. EFAs are grouped into two types: omega-3 and omega-6. An imbalance leading to much higher levels of omega-6s than omega-3s can trigger problems with mood, cognition, and behaviour (Genuis, 2006; Ruxton et al., 2004; Yehuda et al., 1999; Young & Conquer, 2005).
Ideally, the balance should be 2.3 (omega-6) to 1 (omega-3). However, the modern North American diet is rich in omega-6s and poor in omega-3s, and so the ratio is typically more than 10 to 1 (Kris-Etherton et al., 2000).
Natural Sources of Omega-6 and Omega-3 Fatty Acids
Foods that contribute to high omega-6 levels include cooking oils such as corn oil, soybean oil, and canola oil; processed foods; grains; milk; meat; and poultry. However, more natural feeding of animals increases the levels of omega-3s in animal based foods: organic milk (Dewhurt et al., 2003), grass-fed beef (Clancy, 2006), and organic eggs (Karsten, 2003; Long & Alterman, 2007) are all higher in omega-3s than products from grain-fed animals.
Good sources of omega-3s include fatty fish such as cod, halibut, mackerel, herring, trout, sardines, and salmon, as well as olive oil, eggs, and walnuts.
Omega-3s can also be obtained via fish oil capsules, flavoured chewables, and custards. In addition, there are omega-3 supplements made from flaxseed oils and algae, but they are not as effective. As yet, there has not been sufficient research conducted to establish optimal doses for omega-3 supplements.
Evidence for the Role of EFAs in Autism
According to Tamiji and Crawford (2010, p. 99): “The emerging evidence implies that abnormal fatty acid metabolism may play a contributing role in the pathology of autism. Recent literature suggests that fatty acid homeostasis may be altered in autism as a result of insufficient dietary supplementation, genetic defects, function of enzymes involved in their metabolism, or influence of various environmental agents such as infections, inflammation or drugs.”
Dr. Andrew Stoll (2005) cites the following indirect evidence for the EFA deficiency hypothesis:
- Autistic children have been found to be low in omega-3s, but not omega-6s, throwing the balance off (Vancassel et al., 2001).
- Low levels of omega-3s have been associated with behaviour problems, temper tantrums, sleep difficulties, learning problems, and health issues in boys aged 6-12 (Stevens et al., 1996).
Therefore, it’s possible that insufficient omega-3 levels (or too much omega-6 in relation to omega-3) may cause or exacerbate autistic symptoms.
Studies of Omega-3 Supplements as a Treatment for Autism Symptoms
There is some evidence that omega-3 supplements are beneficial for treating some of the problems that are often associated with autistic spectrum disorders. A double-blind, placebo-controlled study conducted by Richardson and Montgomery (2005) investigated the effects of omega-3 supplementation for children with dyspraxia (a motor disorder that tends to be accompanied by behavioural, social, and cognitive problems). Supplementation led to significant gains in behaviour, spelling, and reading (though not motor skills). Control subjects taking a placebo did not achieve the same gains. Although these findings are promising, it should be noted that a study of autistic adults in Egypt conducted by Politi et al. (2008) found no improvements after six weeks of fish oil supplementation. However, this study was quite small (just 19 subjects), and participants were severely autistic.
Amminger et al. (2007) conducted a small EFA trial with 13 autistic-spectrum children who were prone to aggression, tantrums, or self-injury. After six weeks of EFA supplementation, hyperactivity was reduced in the omega-3 group but not the placebo group. No significant adverse side effects were noted in the supplement group.
Bent et al. (2009) conducted a systematic review of research to “determine the safety and efficacy of omega-3 fatty acids for autistic spectrum disorder,” finding that of the 6 studies that met their inclusion criteria, 1 noted improvements in stereotypies and hyperactivity and 4 of the other 5 cited improvements in various outcomes encompassing learning, language, behaviour, health, and anxiety. However, because these studies were all quite small (very few subjects) and only one was a randomized controlled trial, the authors concluded that there is not yet sufficient scientific evidence to prove the efficacy of this intervention.
Autism Research Institute parent ratings of the use of EFA supplements for autism indicate that a slim majority (56%) saw improvements, 41% no change, and 2% a worsening of symptoms. Results were even better for Asperger’s syndrome, with 65% of parents reporting improvements, 33% no change, and only 2% a worsening of symptoms.
EFA Supplement Side Effects and Safety
According to Healing Thresholds (2012), an autism treatment information website with well-researched content overseen by qualified medical reviewers, EFA supplementation at normal doses is not known to trigger major side effects, but high levels can be toxic, and some fish oil supplements may be contaminated by hormones, heavy metals, PCBs, and dioxins, so it’s important to be choosy about supplements (they should be pharmaceutical grade, purified, and tested for contaminants).
More Information on Autism Supplements
For more on the effectiveness of other supplements for treating autistic spectrum disorders, see the main Autism Supplements page. For a full list of articles on autism and Asperger’s syndrome, visit the main Autistic Spectrum Disorders page.
Always consult a qualified medical practitioner before taking supplements or giving them to your child. Many supplements are toxic at certain doses and may interact with some medications or create problems for people with certain medical conditions.
This article is not intended as a substitute for medical consultation or care. Health concerns should be referred to a doctor.
- Amminger, G.P.; Berger, G.E.; Schäfer, M.R.; Klier, C.; Friedrich, M.H.; & Feucht, M. (2007). “Omega-3 Fatty Acids Supplementation in Children With Autism: A Double-Blind Randomized, Placebo-Controlled Pilot Study.” Biological Psychiatry, 61(4), pp. 551-553.
- Autism Research Institute. (2008). “Parent Ratings for Autism” and “Parent Ratings for Asperger’s Syndrome.” Autism.com.
- Bent, S.; Bertoglio, K.; & Hendren, R.L. (2009). “Omega-3 Fatty Acids for Autistic Spectrum Disorder: A Systematic Review.” Journal of Autism and Developmental Disorders, 39(8), pp. 1,145-1,154.
- Clancy, K. (2006). Greener Pastures: How Grass-Fed Beef and Milk Contribute to Healthy Eating. Union of Concerned Scientists, USCUSA.org.
- Dewhurst, R.J.; Fisher, W. J.; Tweed, J.K.S.; & Wilkins, R.J. (2003). “Comparison of Grass and Legume Silages for Milk Production. Production Responses with Different Levels of Concentrate.” Journal of Dairy Science, 86(8), pp. 2,598-2,611.
- Genuis, S.J., & Schwalfenberg, G.K. (2006). “Time for an Oil Check: The Role of Essential Omega-3 Fatty Acids in Maternal and Pediatric Health.” Journal of Perinatology, 26(6), pp. 359-365.
- Healing Thresholds. (2012). “Autism Therapy: Essential Fatty Acids (EFA).” Autism.HealingThresholds.com.
- Karsten, H., PhD. (2003). “Pasture-ized Poultry.”Penn State Online Research, 24(2). RPS.PSU.edu.
- Kris-Etherton, P.M.; Shaffer Taylor, D.; Yu-Poth, S.; Huth, P.; Moriarty, K.; Fishell, V.; Hargrove, R.L.; Zhao, G.; & Etherton, T.D. (2000). “Polyunsaturated Fatty Acids In The Food Chain In The United States.” American Journal of Clinical Nutrition, 71(1), pp. 179S-188S.
- Long, C., & Alterman, T. (2007). “Meet the Real Free-Range Eggs.” Mother Earth News, MotherEarthNews.com.Politi, P.; Cena, H.; Comelli, M.; Marrone, g.; Allegri, C.; Emanuele, E.; & Ucelli di Nemi, S. (2008). “Behavioral Effects of Omega-3 Fatty Acid Supplementation in Young Adults with Severe Autism: An Open Label Study.” Archives of Medical Research, 39(7), pp. 682-685.
- Richardson, A.J., & Montgomery, P. (2005). “The Oxford-Durham Study: A Randomized, Controlled Trial of Dietary Supplementation with Fatty Acids in Children with Developmental Coordination Disorder.” Pediatrics, 115(5), pp. 1,360-1,366.
- Ruxton, C.H.; Reed, S.C.; Simpson, M.J.; & Millington, K.J. (2004). “The Health Benefits of Omega-3 Polyunsaturated Fatty Acids: A Review of the Evidence.” Journal of Human Nutrition and Dietetics, 17(5), pp. 449-459.
- Stevens, L.J.; Zentall, S.S.; Abate, M.L.; Kuczek, T.; & Burgess, J.R. (1996). “Omega-3 Fatty Acids in Boys with Behavior, Learning, and Health Problems.” Physiology and Behavior, 59(4-5), pp. 915-920.
- Stoll, A.L., MD (2005). “Omega 3 Fatty Acids in Autism and other Neuropsychiatric Disorders. [PPT]” DrClaudiaanrig.com.
- Tamiji, J., & Crawford, D.A. (2010). “The Neurobiology of Lipid Metabolism in Autism Spectrum Disorders.” Neurosignals, 18, pp. 98-112.
- Vancassel, S.; Durand, G.; Barthélémy, C.; Lejeune, B.; Martineau, J.; Guilloteau, D.; Andrès, C.; & Chalon, S. (2001). “Plasma Fatty Acid Levels in Autistic Children.” Prostaglandins, Leukotrienes and Essential Fatty Acids, 65(1), pp. 1-7.
- Yehuda, S.; Rabinovitz, S.; & Mostofsky, D.I. (1999). “Essential Fatty Acids are Mediators of Brain Biochemistry and Cognitive Functions.” Journal of Neuroscience Research, 56(6), pp. 565-570.
- Young, G., & Conquer, J. (2005). “Omega-3 Fatty Acids and Neuropsychiatric Disorders.” Reproduction, Nutrition, Development, 45(1), pp. 1-28.