Friday, 3 April 2015

Improving inattention in boys with and without ADHD

The [truncated] PubMed listing of the abstract by Dienke Bos and colleagues [1] does little justice to the results reported by this group looking at the effects of omega-3 fatty acid supplementation on the behaviour of boys both diagnosed with ADHD (attention-deficit hyperactivity disorder) and those who are described as 'typically developing'.

Luckily the paper is open-access (see here) and one can get a true flavour of what happened to this cohort of boys with and without a diagnosis of ADHD following consumption of "10 grams of margarine daily, enriched with either 650mg of EPA/DHA [Eicosapentaenoic Acid / Docosahexaenoic Acid] each or placebo." Indeed, the study is also listed on ClinicalTrials.gov too (see here) and has received some press attention too (see here).

So:

  • Authors "set out to investigate the effects of omega-3 PUFA [polyunsaturated fatty acid] dietary supplementation on ADHD symptoms in young boys with and without ADHD in a randomized, placebo-controlled trial." Randomised [placebo-controlled] trials are sweet music to science ears.
  • As mentioned, researchers did not however limit their analysis of any potential effects from fatty acid supplementation to just boys diagnosed with ADHD. No, instead they "included a typically developing reference group to investigate the specificity of treatment to subjects with ADHD."
  • Over 16 weeks of supplementation (or not) and including measures at baseline (before intervention), researchers assessed the strength of any results based on both psychometric and other more physiological measures including buccal (cheek) swabs "for analysis of phospholipid fatty acid levels" and urine samples to "measure the HVA [homovanillic acid] to creatinine ratio, as a proxy for dopamine turnover." They also imaged the brain via fMRI.
  • Results: "Omega-3 PUFA dietary supplementation improved symptoms of inattention in boys with and without ADHD in a double blind randomized controlled trial." This was based on scores on the Child Behavior Checklist (CBCL) and in particular, scores around attention. Inattention scores were not unexpectedly higher in boys diagnosed with ADHD but the authors are pretty adamant that "there was an effect of treatment on parent-rated symptoms of ADHD, regardless of diagnosis."
  • "The dietary intervention affected omega-3 PUFA levels in cheek cell phospholipids." This gives us some idea that the behavioural changes reported also correlated with a physiological difference over placebo. It doesn't confirm the possible mechanism but is a good start linking behaviour and physiology. Other more physiological variables such as urinary HVA and the fMRI results did not show any specific effects following active intervention.
  • The authors conclude: "this study provides new evidence that dietary supplementation using omega-3 PUFAs may be an effective augmentation of pharmacological treatments of ADHD."

These are interesting results which add to a growing body of work suggesting that PUFAs may have some important effects when it comes to behaviour. With ADHD specifically in mind, PUFAs have received a mixed response from science albeit with some more recent meta-analyses now starting to come down on the side of (possible) effect over no effect, at least for some (see here). Outside of just ADHD, there is also a bank of research suggesting that skills such as reading ability might also have some connection to PUFA status (see here) again, for some. I say this with the caveat that there is more research to do in these areas.

As per the discussions by Bos, their study was of a particularly high methodological standard so that must count in favour of strength of their results. They did note that "a small number of participants with ADHD had changes made to their medication during the intervention" but found similar results without including these participants in separate analysis. With those issues in mind, I'd be inclined to say that we should be paying a lot more attention to fatty acids and behaviour...

Music: Bobby Fuller Four - I Fought The Law.

----------

[1] Bos DJ. et al. Reduced symptoms of inattention after Dietary Omega-3 Fatty Acid Supplementation in boys with and without Attention Deficit/Hyperactivity Disorder. Neuropsychopharmacology. 2015 Mar 19.

----------

ResearchBlogging.org Bos DJ, Oranje B, Veerhoek ES, Van Diepen RM, Weusten JM, Demmelmair H, Koletzko B, de Sain-van der Velden MG, Eilander A, Hoeksma M, & Durston S (2015). Reduced symptoms of inattention after Dietary Omega-3 Fatty Acid Supplementation in boys with and without Attention Deficit/Hyperactivity Disorder. Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology PMID: 25790022