Friday, 6 May 2011

Moggies best friend - fish oils and autism

Childhood memories - school, playing football in the park with my two left feet, conkers - and ah yes, cod liver oil. "Open wide" and then the big dessert spoon of the most foul-smelling, fish-gut tasting 'gruel' is poured down your throat, followed by that spine-shaking 'euch' feeling as yet another dose of cod liver oil had been administered.

"It will keep you regular" is the excuse I often heard. I'm not quite sure that it ever did 'keep me regular' and also if it did, it was little consolation for the fish-breath that I passed to my school chums for the rest of the day. I was however very popular with the neighbourhood moggies. In more recent times, cold liver oil (CLO) has undergone a little bit of a PR make-over.

Gone is the smelly oil from an old Boots medicine bottle to be replaced by things like gelatin capsules, whose oils now smell and taste of citrus or vanilla (with a hint of fish). We don't even call it CLO anymore; now it is 'omega-3 fatty acids' and even fish fingers tell us that they are high in omega 3 - a revelation indeed. The PR machine has truely sanitised CLO. Nowadays also, omega-3 (n-3) fatty acids don't just claim to keep you regular. No, now they make you smarter (apparently), make you more heart healthy and potentially help in quite a few conditions. All from our humble fish.

n-3 fatty acids in relation to autism and various other developmental conditions has also received more than a passing mention. I will say at this point that such use has not been without its critics; but in the spirit of science, I am going to stay away from the mudslinging and focus on what the research describes. We know that there are a proportion of people with autism who, for one reason or another, seem to present with lower levels of n-3 fatty acids compared to various control groups. This paper was one of the first to suggest such a notion, building on findings from a smaller participant group included in a paper from Gordon Bell and colleagues at Stirling University. The more up-to-date work seems to follow a similar trend.

An imbalance of the n-6/n-3 ratio seems to be a key finding and as a result, research has turned its eye to what happens when you try and correct the discrepancy via n-3 supplementation. The evidence for effect is a little hit-and-miss at the moment.

Paul Amminger's paper represents the first well-controlled trial of n-3 fatty acids for autism. Compared with placebo, n-3 fatty acids were reported to positively affect stereotypy and hyperactivity in his small participant group. The 'hyperactivity' side of things complements trial results from n-3 supplementation for ADHD and some more recent work on levels of n-3 and school performance in the general population.

Meow, I hear you say - where I can I get some of them? Well, just wait a minute or two. Other authors have not been so positive in their outlook of supplementation. This trial of n-3 supplementation with adults with severe autism showed nothing in terms of significant positive results. This trial suggested a similar outcome albeit balanced by a small sample size and some potential non-significant effects.

Why the discrepancy? Well, we have different groups being looked at with regards to age, symptom severity, and outcome measures used. Outcome measures are an important part of any study (i.e. making sure they examine the right things) which I might come back to in a later post. Remember also my n=1 notion. We also have different preparations being used all coming under the 'fatty acid' banner but perhaps slightly different in their formulation (EPA, DHA), and also perhaps importantly in their co-ingredients.

If I were to generalise (grumble, grumble), the limited results so far seem to suggest that co-morbid conditions to autism such as hyperactivity seem to be the 'target' symptom of n-3 supplementation. Mmm, reminds me of another autism intervention potentially targetting the same co-morbidity.... Perhaps more research required?

So there you have it. Smelly old CLO transformed Gok Wan style to trendy 'fatty acids'. New branding, new effects, but same old stuff. Here kitty, kitty, kitty.