Childhood dietary patterns and ADHD?

The findings of the systematic review and meta-analysis published by Bianca Del-Ponte and colleagues [1] provide the blogging fodder today, and the suggestion that: "a diet high in refined sugar and saturated fat can increase the risk, whereas a healthy diet, characterized by high consumption of fruits and vegetables, would protect against ADHD [attention-deficit hyperactivity disorder] or hyperactivity."

The starting point: "The diet during childhood has been investigated as a factor potentially involved in the ADHD etiology." Yes it has, and Del-Ponte et al managed to find 14 studies looking at this issue published in the peer-reviewed literature. The data were boiled down and results obtained suggesting that "healthy dietary patterns were protective against ADHD (OR: 0.65; 95% CI: 044 – 0.97), while unhealthy dietary patterns were found as risk to ADHD (OR: 1.41; 95% CI: 1.15–1.74)."

The authors admit that the science upon which they made their observation is "weak" insofar as cause and effect not being proved. This is an important point (see here) that follows other research in this area too (see here and see here) together with an understanding that many different variables *might* influence the risk of something like ADHD as a diagnosis or in behaviour (see here and see here for examples).

Still, if there is even the remotest possibility that diet might be something to consider in respect of ADHD, adding it to the intervention arsenal that already exists (see here) can only be a good thing...

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[1] Del-Ponte B. et al. Dietary patterns and attention deficit/hyperactivity disorder (ADHD): A systematic review and meta-analysis. Journal of Affective Disorders. 2019; 252: 160-173.

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The pharmacological and non-pharmacological treatment of paediatric ADHD

The findings - "systematic review with network meta-analyses" - reported by Ferrán Catalá-López and colleagues [1] (open-access available here) on the topic of treating attention-deficit hyperactivity disorder (ADHD) were expected [2].

Looking at the available peer-reviewed science comparing "the efficacy and safety of pharmacological, psychological and complementary and alternative medicine interventions for the treatment of ADHD in children and adolescents" authors identified nearly 200 randomised trials looking at various intervention options. With data from over 26,000 people diagnosed with ADHD to examine, they applied some nifty statistical analyses leading to various conclusions on the basis of their categorisations of the various interventions analysed: "pharmacological (stimulants, non-stimulants, antidepressants, antipsychotics, and other unlicensed drugs), psychological (behavioural, cognitive training and neurofeedback) and complementary and alternative medicine (dietary therapy, fatty acids, amino acids, minerals, herbal therapy, homeopathy, and physical activity)."

First: "behavioural therapy (alone or in combination with stimulants), stimulants, and non-stimulant seemed significantly more efficacious than placebo." I don't think this is a particularly novel finding given the intervention options typically indicated for ADHD (see here).

Then: "Behavioural therapy in combination with stimulants seemed superior to stimulants or non-stimulants." This is important insofar as any notion that use of pharmacotherapy alone is going to 'tackle' ADHD. It also suggests that parents, teachers and significant others have a role to play in managing the symptoms of childhood ADHD as per various examples (see here).

Also: "Most of the efficacious pharmacological treatments were associated with harms (anorexia, weight loss and insomnia), but an increased risk of serious adverse events was not observed." It should be no surprise to anyone that there is a cost-benefit balance to be struck when it comes to pharmacotherapy for ADHD or anything else. Medicines always have the potential for side-effects. The lack however, of 'serious adverse events' noted by Catalá-López et al is reassuring and adds to other reviews (see here) highlighting a role for regular monitoring and good medicines management with specific regards to medicines indicated for ADHD.

Finally: "There is lack of evidence for cognitive training, neurofeedback, antidepressants, antipsychotics, dietary therapy, fatty acids, and other complementary and alternative medicine." I don't disagree with these findings but do find it a little 'odd' that other systematic reviews/meta-analyses of something like dietary interventions and/or use of fatty acids for ADHD have come to slightly different conclusions (see here and see here respectively). I don't doubt that there are going to be some subtle differences in what studies were included for further analysis and the interpretation of findings, but 'lack of evidence' is, in my mind at least, perhaps not an entirely accurate viewpoint. Indeed, a more recent paper is a further case in point [3].

"An open and honest discussion with parents and older children about uncertainties of available treatments and the balance between benefits, costs, and potential harms should be established before starting treatment." I think a sentence like this should be added to every article trying to arrive at a coherent statement for many different behavioural and psychiatric labels. It tells us that whilst scientific progress is being made when it comes to the important management of ADHD (see here), there typically is no one-size-fits-all 'silver bullet' that will vanquish all of the challenging symptoms of ADHD and onward improve current and future quality of life. Added to the idea that a multi-pronged approach to managing ADHD is typically better than any one single intervention option, and the Catalá-López article might turn out to be something rather important for many different people with various degrees of interest in ADHD and beyond.

Music: and when Mars Attacks...

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[1] Catalá-López F. et al. The pharmacological and non-pharmacological treatment of attention deficit hyperactivity disorder in children and adolescents: A systematic review with network meta-analyses of randomised trials. PLoS One. 2017 Jul 12;12(7):e0180355.

[2] Catalá-López F. et al. The pharmacological and non-pharmacological treatment of attention deficit hyperactivity disorder in children and adolescents: protocol for a systematic review and network meta-analysis of randomized controlled trials. Systematic Reviews. 2015;4:19.

[3] Chang JC. et al. Omega-3 Polyunsaturated Fatty Acids in Youths with Attention Deficit Hyperactivity Disorder (ADHD): A Systematic Review and Meta-Analysis of Clinical Trials and Biological Studies. Neuropsychopharmacology. 2017 Jul 25.

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A few-foods diet for ADHD: a systematic review of meta-analyses of double-blind, placebo-controlled trials

"... the effect sizes of a few-foods diet are medium to large, justifying implementation of a diagnostic FFD [few-foods diet] in subgroups of children with ADHD [attention-deficit hyperactivity disorder], thus offering innovative treatment opportunities for ADHD."

So said the "Systematic Review of Meta-Analyses of Double-Blind Placebo-Controlled Trials" published by Lidy Pelsser and colleagues [1] (open-access available here) looking at various dietary interventions that have been studied with ADHD in mind. Pelsser, I might add, is a name not completely unfamiliar to this area of investigation as per other research on elimination diets and ADHD (see here).

The few-foods diet mentioned in the opening sentence of this post, could include a few things but Pelsser et al make specific reference to it consisting of "lamb, chicken, potatoes, rice, banana, apple and brassica: foods chosen as they were unlikely to produce an adverse response." You'll perhaps note that there are a few food groups missing from that list of foods, not least the grains (including the gluten protein), dairy products (containing the casein protein) and those processed foods that we all like to enjoy.

The Pelsser paper is an interesting one insofar as their systematically reviewing meta-analyses that were already conducted on dietary intervention(s) for ADHD. Said meta-analyses included in their paper were only allowed in if they meta-analysed double-blind placebo-controlled trials (the gold-standard of clinical trial design). If one assumes that a meta-analysis - where data from different trials is analysed and condensed into a sort of position statement - sits at the top of the evidence-based science hierarchy, the Pelsser study design perhaps sits on top of the top!

Although the FFD receives some welcome scientific backing in the review paper, it was not the only dietary intervention looked at the Pelsser and colleagues. To quote: "six supplement meta-analyses—all investigating the effects of poly-unsaturated fatty acids (PUFA)... —and eight elimination meta-analyses, examining respectively the effects of sugar..., AFC [artificial food colour elimination]..., the Feingold diet..., and the FFD... on ADHD" were reported on. The other interventions did not - for various possible reasons - match up to the research success reported with regards to the current standing of the few-foods diet for ADHD. This included the story on fatty acids for ADHD which has been mentioned previously on this blog (see here for example).

I do not make recommendations on this blog when it comes to intervention and the like for anything. I will however, once again quote Pelsser et al based on their very thorough analysis of the peer-reviewed science in the area of dietary intervention for ADHD: "the effect sizes of a few-foods diet are medium to large, justifying implementation of a diagnostic FFD in subgroups of children with ADHD, thus offering innovative treatment opportunities for ADHD". Also: "FFD research should focus on the mechanism of food in children with ADHD." Their words not mine, and based on some rather credible evidence. I might also add that appropriate dietetic input is a must before anyone heads into the FFD willy-nilly and no, this is not about 'clean eating' or any related fad...

And just before you go, how about casting your eye over the observations made by Alejandra Ríos-Hernández and colleagues [2] and their raising the question of "whether low adherence to a Mediterranean diet might play a role in ADHD development"? Food for thought in the context of the Pelsser data, although perhaps minus the [pregnancy] licorice?

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[1] Pelsser LM. et al. Diet and ADHD, Reviewing the Evidence: A Systematic Review of Meta-Analyses of Double-Blind Placebo-Controlled Trials Evaluating the Efficacy of Diet Interventions on the Behavior of Children with ADHD. PLoS One. 2017 Jan 25;12(1):e0169277.

[2] Ríos-Hernández A. et al. The Mediterranean Diet and ADHD in Children and Adolescents. Pediatrics. 2017. Jan 30.

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Pelsser LM, Frankena K, Toorman J, & Rodrigues Pereira R (2017). Diet and ADHD, Reviewing the Evidence: A Systematic Review of Meta-Analyses of Double-Blind Placebo-Controlled Trials Evaluating the Efficacy of Diet Interventions on the Behavior of Children with ADHD. PloS one, 12 (1) PMID: 28121994