Saturday September 16, 2006
Regular readers will have established by now that most journalists are so scientifically inept, and so eager to run with â€œpill solves complex social problemâ€ stories, that companies like Equazen selling their Eye-Q fish oil tablets for children with blanket media coverage can come out very nicely indeed.
So hereâ€™s the background you might have missed. Firstly, it costs 80p a day for you to feed your child these Eye-Q omega-3 fish oil tablets that Equazen have provided for Durham Council, to give to their GCSE students, in last weekâ€™s fish oil â€œtrialâ€ which received such phenomenal widespread media adulation. Meanwhile, Durham Council spend 65p a day on the ingredients for the same childrenâ€™s school meals. If I was going to get to work on improving childrensâ€™ diets, Durham, let me tell you, I would not start with pills, nor would I start with the long promotional press releases that you have been sending out with Equazenâ€™s press office contact details on the bottom.
Dave Ford from Durham Council, the man behind these fish oil â€œtrialsâ€, thinks that the evidence on omega-3 for intelligence and behaviour is in, and that this evidence shows it is of benefit. Well now, letâ€™s go through the five published papers shall we: skip to the end for a punchline if you find evidence boring.
Not a single one of these trials is in â€œnormalâ€ mainstream children, 3 were positive (to a greater or lesser extent, as you will see), two were negative. Voigt et al in 2001 did a double-blind, randomised, placebo-controlled trial on omega-3 fish oil in 63 kids with ADHD: they found no significant differences between the fish oil and control groups (full citations and precis for all studies on badscience.net). Richardson et al in 2002 did a trial on 41 children with learning difficulties, and found improvements in 3 out of the 14 things measured (Conners ADHD score, inattention, and psychosomatic symptoms). Stevens et al in 2003 did a pilot study on 50 children with inattention, hyperactivity, and other disruptive behaviors (one third dropped out during the trial) and found improvements in the fish oil group for 2 out of the 16 things measured (parent-rated conduct problems and teacher-rated attention symptoms).
Weâ€™re nearly there. This is important. Hirayama et al had a trial with 40 subjects with ADHD, and in fact, not only was there no improvement for the fish oil group, the placebo group showed a significant improvement in visual short term memory and continuous performance. And lastly Richardson et al, looking at 117 subjects with developmental coordination disorder, found no significant differences between placebo and fish oil groups for motor skills, but improvements in reading and spelling. This last one, incidentally, was the â€œOxford-Durhamâ€ trial, performed by Oxford academics, published in a peer reviewed academic journal, and it has nothing whatsoever to do with these unpublished methodologically inept â€œDurham trialsâ€ now being performed by Equazen’s friends in Durham County Council.
Why does Dave Ford of Durham Council think the case is proven? Why does Equazen think the case is proven? Why does the entirety of the media think the case is proven?
Because Equazen keep going on about all these trials theyâ€™ve done, and they keep getting reported all over the newspaper and telly. â€œAll of our research, both published and unpublished, shows that the Eye Q formula can really help enhance achievement in the classroomâ€ says Adam Kelliher, director of Equazen. All of it? I tried to get all of these studies (there are 20 now, apparently) so I could read them. â€œNullius in verbaâ€ is the Royal Societyâ€™s motto: â€œon the word of no-oneâ€. This isnâ€™t childishness. Iâ€™m not accusing people of lying. I simply want to read the research, in full, see their methodology, and results, and statistics, in full, critically appraise it, like you do, when you read a piece of academic research. Thatâ€™s what science is all about. Itâ€™s about not taking things on faith or authority.
But I couldnâ€™t read them. These studies are not published, and Equazen told me I would have to sign a confidentiality agreement to see them: a confidentiality agreement, to review the research evidence for these incredibly widely reported claims, in the media and by Durham Council employees, about a very interesting and controversial area of nutrition and behaviour, and about experiments conducted – forgive me if Iâ€™m getting sentimental here – on our schoolchildren. Well I suppose I could have signed it just to find out for my own curiosity. You wouldnâ€™t even know if I had.
These are the five published trials looking at what happens in children (with various diagnoses) when you give them fish oil supplements. I do not wish to undermine these studies in any sense, but it is worth noting, along with your other readings around them, that in most only a small number of the many variables measured were changed by fish oil, and that the p-values in the variables that were found to be changed were only just below 0.05, that is, they did just reach statistical significance. If you disagree with any of these brief summaries or have anything to add to them then do please let me know. In general, you will see if you get the original papers that they were methodologically meticulous and reported to a high standard. Top Jadad scores all round.
Voigt, R.G. et al., A randomized, double-blind, placebo-controlled trial of docosahexaenoic acid supplementation in children with attention- deficit/hyperactivity disorder. Journal of Pediatrics, 2001. 139(2): p. 189-96.
Kids with ADHD, found no significant differences in objective or subjective ADHD measures between treatment and control group. 63 subjects, 14.3% dropped out.
Richardson, A.J. et al., A randomized double-blind, placebo-controlled study of the effects of supplementation with highly unsaturated fatty acids on ADHD- related symptoms in children with specific learning disabilities. Progress in Neuro-Psychopharmacology & Biological Psychiatry, 2002. 26(2): p. 233-239.
Kids with LD, improvements in Conners ADHD score, inattention, and psychosomatic symptoms (P = 0.05, 0.03, 0.05 respectively) (3 out of the 14 things measured). 41 subjects, 22% dropped out.
Stevens, L.Z. et al. EFA supplementation in children with inattention, hyperactivity, and other disruptive behaviors. Lipids, 2003. 38(10): p. 1007-21.
Kids with ADHD or other disruptive behaviours, only a pilot study, improvements in fish oil group for parent rated conduct problems (p=0.05) & attention teacher rated symptoms (P=0.03) (2 out of the 16 things measured). 50 subjects, 34% dropped out.
Hirayama, S. et al., Effect of docosahexaenoic acid-containing food administration on symptoms of attention-deficit/hyperactivity disorder – a placebo-controlled double-blind study. European Journal of Clinical Nutrition, 2004. 58(3): p. 467-73.
Kids with ADHD, no difference between placebo and fish oil group (oh, except the placebo group, rather than the fish oil group, showed a significant improvement in visual short term memory and continuous performance). 40 subjects.
Richardson, A.J. and Montgomery, P., The Oxford-Durham study: a randomized, controlled trial of dietary supplementation with fatty acids in children with developmental coordination disorder. Pediatrics, 2005. 115(5): p. 1360-6.
Kids with Developmental Coordination Disorder, no significant differences between placebo and fish oil groups for motor skills, but improvements for the fish oil group in reading and spelling (P= 0.04 and <0.01) and CTRS-L global scale (P<0.05) and some subscale improvements (P<0.05) for the fish oil group. 117 subjects, 6% dropped out.
Incidentally, for those of you haven’t been back to the blog in the past few days, if you have the stomach for very long posts, you might enjoy this slightly odd episode from the previous comments:
followed by amusing banter, and then stirring rebuttal here: