Fatty acids and autism meta-analysed again (yet again)

"Our preliminary meta-analysis suggests that supplementation of omega 3 fatty acids may improve hyperactivity, lethargy, and stereotypy in ASD [autism spectrum disorder] patients."

So said the results of the meta-analysis of randomized controlled trials undertaken by Yu-Shian Cheng and colleagues [1] adding further to this interesting area of nutrition with autism in mind. Before venturing through the results, I'll draw your attention to two other occasions this year when fatty acids use and autism have been given the meta-analysis treatment (see here and see here) albeit coming to slightly different conclusions.

This time around six studies made the grade for inclusion in the meta-analysis covering nearly 200 participants. All pitted an omega-3 fatty supplement against placebo and discussed study periods ranging from 6 weeks to 24 weeks. Various schedules were used to measure the impact (if any) of supplementation and/or placebo but the Autism Behavior Checklist (ABC) seemed to be one of the more frequently used assessment scales.

Results: bearing in mind "the average Jadad score was 4.67 with a standard deviation of 0.52" denoting that the methodological quality of the collected literature was pretty good, authors reported a general skewing trend towards 'better response by omega 3' over that of response to the placebos used by the various studies. This covered various areas of both core autistic behaviour(s) such as stereotypy and other, quality of life affecting parameters such as hyperactivity.

But... the clinical picture was not so clear-cut when it came to other autism-related measures such as the SRS - Social Responsiveness Scale - where "there was only borderline improved response by placebo in SRS total scores than those by omega 3." Taking into account the collected results, I do wonder whether use of something like an omega-3 supplement with autism in mind might actually be more relevant to the presence of co-occurring attention-deficit hyperactivity disorder (ADHD) given that (a) ADHD is very much over-represented in relation to autism (see here) and (b) the evidence base on the use of fatty acid supplements for ADHD seems to show a much more 'clear' positive relationship (see here).

There is another point raised in the Cheng paper that is worth noting: "Meta-analysis demonstrated no significant difference in the rate of discontinuation due to side effects between children receiving omega 3 and those treated by placebo." Although this does not mean that fatty acid supplements are universally 'side-effect' free, it does provide some good evidence that such supplementation was generally well-tolerated by the cohorts included for study. I say this bearing in mind that: "Gastrointestinal discomfort and irritability were most commonly reported side effects in the omega 3 groups" understanding that gastrointestinal (GI) issues are already over-represented when it comes to autism (see here).

Minus sweeping generalisations and keeping in mind the prime directive of this blog - no medical or clinical advice is given or intended - I have to say that the peer-reviewed science base for using omega-3 fatty acid supplements in the context of autism (or autism+ADHD?) is looking rather favourable. I say that in connection to the behavioural data that has so far been produced following supplementation but also more generally, with population evidence that omega-3 supplement seems to be good for aspects of physical health and wellbeing too. Certainly, the risk-benefit profile of fatty acid supplementation seems to favour benefit over risk...

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[1] Cheng Y-S. et al. Supplementation of omega 3 fatty acids may improve hyperactivity, lethargy, and stereotypy in children with autism spectrum disorders: a meta-analysis of randomized controlled trials. Neuropsychiatric Disease and Treatment 2017: 13  2531–2543.

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