Therapeutic Effects of Omega-3 Fatty Acids on Challenging Behaviors of Autistic Individuals

There are enormous amounts of both anecdotal and randomized, double-blind, placebo-controlled studies about the neurobehavioral mechanisms of Omega-3 Fatty Acids in psychiatric disorders and Autism Spectrum Disorders (ASD) (Meguid, et. al. 2008; Kidd, 2007; Clayton, et. al., 2007; Sliwinski , et. al., 2006; Amminger, et al., 2006; Vaisman, et. al., 2006; Parker, et. al. 2006; Gustafsson, et. al., 2004; Longan, 2003; Marangell, et. al., 2003; Bell, et. al, 2002; McCrone, 2002; Peet, 2002; Vancassel, et al., 2001; Fenton, et. al., 2000; Stoll, et. al. 1999; Bourre, et. al. 1993; Hibbeln, et. al., 1995.)

Essential fatty acids such as omega-3 are long-chain polyunsaturated fatty acids found in various plants and marine animals that cannot be synthesized in the human body, and are important for normal cellular function. The three major omega 3 fatty acids are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

(Lippincott Williams and Wilkins, 1999)

Normally, we can convert ALA to EPA and DHA, which are the forms that we can metabolize. However, recent evidence shows that the capacity to produce EPA and DHA from ALA is limited and unlikely to supply requirements, especially in rapidly growing young children (Agostoni, et. al. 1995).

Omega-3 fatty acids are considered an important element in normal brain development. According to several researchers (Bourre, et al. 1991, 1993; Yehuda, et al., 1999 & Vancassel, et al., 2001), the human brain is the second organ that contains the highest concentration of polyunsaturated fatty acids (PUFA). In the nervous system, one out of every three fatty acids belongs to the polyunsaturated fatty acids group (Bourre, et al., 1991 & Yehuda, et al., 1999). Some studies suggest that the levels of polyunsaturated fatty acids are lower in autistic individuals, in comparison with normal populations (Kidd, 2007.)

Autism Spectrum Disorder has a very complex etiology and core symptom domains such as “qualitative impairment in social interaction”, “qualitative impairments in communication” and “restricted repetitive and stereotyped patterns of behavior, interests and activities” (DSM-IV). Evidence from research studies have hypothesized that the core symptoms domains are in part due to a developmental disorder of the central nervous system (Trottier, et al., 1999).

Meguid and colleagues (2008) evaluated the correlation between omega-3 and challenging behaviors in a study of 30 children with autism in comparison with 30 healthy children (control group). They found that autistic children treated with linolenic acid (an omega-3) showed 71% reduction in challenging behaviors. Amminger and colleague (2006) provided preliminary evidence that omega-3 fatty acids may be an effective treatment for challenging behaviors in children with autism (hyperactivity and stereotypy behaviors).

A possible explanation for the therapeutic effects of omega-3 on autism has to do with its relationship with pro-inflammatory mediators such as Serotonin. While it is commonly known that Serotonin is a neurotransmitter that regulates neuronal activity in the brain, it is also a product of platelet cells involved in inflammatory reactions. It has a similar action to histamine, in that it also dilates arterioles and increases the permeability of venules.

Eicosapentaenoic acid (EPA), an Omega-3 fatty acid, acts to reduce pro-inflammatory reactions by suppressing the production of mediators such asThromboxane A2 that lead to platelet aggregation and stimulation, and thus release Serotonin and Histamine. Given that Serotonin levels in autistic individuals are elevated above normal and, as some studies suggest, may be related to the pathology of autism, it would be reasonable to consider if Omega-3 can potentially lower Serotonin levels and produce a positive behavioral response in autistic individuals (Anderson, et al., 1987; Sliwinski, 2006.) Serotonin (5-hydroxytryptamine, 5-HT) is derived from the essential amino-acid Tryptophan. Serotonin regulates mood and abnormalities and has been associated with depression, aggression, obsessive-compulsive behaviors, feeding behaviors and obesity.

Croonenberghs and colleagues (2008, 2007, 2005, and 2002) suggested that abnormalities in the inflammatory response system (IRS), may induce some of the behavioral symptoms of autism, such as social withdrawal, resistance to novelty and sleep disturbances. Disorders in the peripheral and central metabolism of Serotonin (5-HT) may play a role in the pathophysiology of autistic disorder (Sliwinski, 2006.) Again, polyunsaturated fatty acids (PUFAs – Omega-3, in particular DHA) are potent suppressors of the Inflammatory Response System (IRS), and currently used as treatment, for instance, of rheumatoid arthritis (Chen, et al., 2005; Young & Conquet, 2005.)

Polyunsaturated fatty acids (PUFA) supplementation may play an important role in ameliorating autistic problematic behavior. Some of the best sources of omega 3 fatty acids are fish, corn, soybean oil and safflower oil. Unfortunately, many fish such as shark, swordfish, and tuna are high in mercury and other toxins, but salmon and shrimp, for instance, tend to have lower levels of mercury. Some studies reported that mercury levels in several USA brands of fish oil capsules are undetectable. High doses of omega-3 may have harmful effects, such as an increased risk of bleeding.

According to the FDA the maximum safe dietary dosage is no more than 3g/day of EPA and DHA from supplements and no more than 2g/day of Omega-3 from the diet (FDA, 2004.)