something fishy here…

It seems that fish oil is back in the news. This morning’s Herald carried an item about a school that’s trialling the use of omega-3 fish oils in enhancing student performance. They obviously haven’t heard of the Durham ‘trials’ in the UK

The paper reports that the school has selected two groups of children for their ‘trial’. One group of 21 students received 1 fish-oil capsule daily for the first month (courtesy of a local supplier) and will take 2 capules a day for two months more. The second group, which is ‘roughly the same’ demographically) attends the same classes but doesn’t get the pills.

And are there any results from this so far? Apparently the students were recently tested on writing skills – the ‘control’ group were at the expected level of achievement, while the ‘trial’ group were above expectations.

So does this demonstrate the efficacy of fish oils in boosting school performance? Well, no, it doesn’t. The ‘trial’ design prevents us from drawing any conclusions in that area. For a start, the two groups weren’t accurately matched demographically. But what’s of more concern is that the trial isn’t double-blinded, let alone randomised. So the students know they’re getting the fish oil capsules. And so do their teachers. So now things are really badly confused. For a start, we have the placebo effect – students know they’re getting something special & probably also know the hoped-for result of the trial. This will affect their performance. And – even further confounding things – their teachers know too. And their own expectations may well colour how they interpret students’ test results.

In other words, this would have far more power as a preliminary investigation if both groups of students were properly matched demographically, AND if the trial was randomised & double-blinded – neither students nor teachers know who’s receiving what treatment.

And a bit of sceptical investigative journalism wouldn’t go amiss either…

3 thoughts on “something fishy here…”

  • I work very closely with radio and television journalism (you could say I’m “in the media”), and I’ve noticed that whatever fact-checking skills and general knowledge journalists do possess is appalling. The Dominion Post here in Wellington runs credulous stories championing the so-called psychics from Sensing Murder. The coverage when scientists mapped the platypus genome was just absurd. I do not know if you read Poneke’s blog (, but he has taken the Dom Post to task for the former issue a few times now.
    I’m starting to want to be an editor one day, simply because I find the content that gets to me is so terribly managed.
    I’ve favourited your blog. Thanks for blogging.

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