UPDATED: Observer plugs fish oil for concentration, ADHD and depression

I was surprised to see the usually excellent Guardian Science tweeting that “Fish oil helps schoolchildren to concentrate”. This linked to Denis Campbell’s Observer article, reporting that

Fish oil helps schoolchildren to concentrate
US academics discover high doses of omega-3 fish oil combat hyperactivity and attention deficit disorder
Children can learn better at school by taking omega-3 fish oil supplements which boost their concentration, scientists say.

Boys aged eight to 11 who were given doses once or twice a day of docosahexaenoic acid, an essential fatty acid known as DHA, showed big improvements in their performance during tasks involving attention.

Dr Robert McNamara, of the University of Cincinnati, who led the team of American researchers, said their findings could help pupils to study more effectively and potentially help to tackle both attention deficit hyperactivity disorder (ADHD) and depression.

Unfortunately, the Observer’s claims about fish oil are not evidence-based.

Madeleine Portwood, fish oil, chemistry and children

We were fascinated to come across a Madeleine Portwood presentation on the Food for the Brain site [PDF]: discussing “Essential Fats, School Performance and Behaviour”. One quote stands out, repeated on two slides alongside pictures of very sweet-looking children:

this is not about chemistry. This is about children.

At a first glance, this sounds very compelling: after all, who could argue with the fact that educational psychology in our schools needs to be about children? However, the dichotomy invoked by Portwood here is extremely problematic. A brief discussion of the Cochrane Collaboration will help to make clear why.

The Cochrane logo features a prominent diagram. The diagram

shows the results of a systematic review of RCTs of a short, inexpensive course of a corticosteroid given to women about to give birth too early. The first of these RCTs was reported in 1972. The diagram summarises the evidence that would have been revealed had the available RCTs been reviewed systematically a decade later it indicates strongly that corticosteroids reduce the risk of babies dying from the complications of immaturity. By 1991, seven more trials had been reported, and the picture had become still stronger. This treatment reduces the odds of the babies of these women dying from the complications of immaturity by 30 to 50 per cent.

Because no systematic review of these trials had been published until 1989, most obstetricians had not realised that the treatment was so effective. As a result, tens of thousands of premature babies have probably suffered and died unnecessarily (and needed more expensive treatment than was necessary). This is just one of many examples of the human costs resulting from failure to perform systematic, up-to-date reviews of RCTs of health care.

Research is about both chemistry and children. Because of suboptimal evaluation of the research into how particular chemicals worked in particular situations, a number of babies will have died who might otherwise have been saved.

It is because we care about children – and because children are important – that we need to insist that research conducted in children and on childhood conditions meets the highest possible standards.

Durham fish oil (non)trial: when is a control group not a control group?

In response to a FOIA request, Durham has told us about another significant flaw in their fish oil (non)trial: the ‘treatment’ arm was students with more than 80% reported compliance with supplementation with Equazen fish oil pills; the ‘control groups was selected from any students with less than 80% reported compliance. This means that – while a student with 80% reported compliance could have counted as an example of the success of this ‘treatment’ – a student with 79% reported compliance could have been compared to them as part of the ‘control group’.

I am really not sure what to say

Durham choosing how to measure success in their fish oil (non)trial: third time lucky?

Looking over the Durham fish oil (non)trial again, I noticed something I had missed: they have previously claimed to be looking at three quite different things in order to determine whether the pills are effective. They started out (back in 2006) with a press release where they promised to measure efficacy by comparing students’ actual GCSE results to their predicted results. Not terribly promising methodologically, but at least Durham were explicit about what was going to be measured. Except that, in their response to a 2008 FOIA request, Durham stated that

All that was being sought was the number of children taking up the offer of capsules and a comparison of GCSE results from the previous year

To me, that sounds rather different. Then, to make matters worse (as we have already noted) Durham eventually chose to measure how fish oil takers compared with ‘matched pairs’ from the same year group. Again, this is a different test of whether the pills work. Those of you wondering why Durham are taking so long to release these results might also be interested to know that the 2006 press release promised that

the first test of the supplement’s effectiveness will be when they sit their ‘mock’ exams this December.

It is good practice to decide what you are measuring – and how you are going to judge the efficacy of a treatment – before starting a trial: otherwise, it can be tempting to change what is measured in order to generate the ‘right’ result. While I cannot know why Durham have discussed plans to measure the ‘success’ of fish oil in this (non)trial in three ways since 2006, this gives yet another reason why it is imperative that Durham release their data ASAP: so that the claims in their press releases can be scrutinised.

Rather than Durham playing third time lucky with tests of efficacy, could this be a case for Einstein creature?

Irish Times: “Holford has been a vegetarian for 30 years”. Has he?

In the course of a truly dire article on Patrick Holford – ‘Eat Your Medicine’ – the Irish Times states that “Holford has been a vegetarian for 30 years”. This seems a peculiar claim: the Independent has previously referred to Holford eating fish, and the Health Products for Life web shop states that Holford takes fish oil pills.

Honestly, I wouldn’t generally care what Holford ate or what pills he takes: if he wants to eat fish, he has every right to do so; he is also quite entitled to take fish oil pills, although I would imagine that the fish is tastier. But Holford makes a big play of his own lifestyle when selling his ideas and his products:

people are motivated to follow my advice because I explain the logic of it and I embody it

Which makes it peculiar for Holford to be described as a vegetarian – and a vegetarian for 30 years, no less – at the same time as discussing eating fish and taking fish oil pills. If fans of ‘alternative’ nutrition are going to base their lifestyle on one other person who happens to be healthy (a pretty daft move in itself – I’m sure we all have anecdotes of people who lived long, healthy lives while smoking and drinking heavily, avoiding exercise, etc.) surely Holford could at least publicise a consistent account of his lifestyle?

Durham fish oil (non)trial and science by press release: it’s unclear what the children were taking

In their continued efforts to provide a textbook example of why science by press release is a very bad thing, Durham Council’s press releases about their fish oil (non)trial even manage to muddy the water as to which Essential Fatty Acids (EFAs) were in the capsules that Durham gave to their schoolchildren. Their latest press release on the issue refers to the “Omega-3 tablets” the children were taking. However, back in 2006 Durham’s press release implied that Equazen’s Eye Q capsules (not tablets) were being used: it quoted Equazen’s Managing Director saying that

the eye q formula can really help enhance achievement in the classroom

Eye Q does not just contain omega 3 fats: it also contains “Omega-6 Gamma Linolenic Acid (GLA) from evening primrose oil and its metabolite Arachidonic Acid (AA)”. However, as well as Durham’s latest press release, recent coverage by the BBC referred to “fish oil” and Omega-3 supplements. The Northern Chronicle also referred to “fish oil capsules”. Ironically, it took an otherwise pretty poor article in the Daily Mail to point out that evening primrose oil was also given to the children.

It might seem like I’m being pedantic, but Equazen clearly view Evening Primrose Oil as significant, claiming that this “also plays a structural role, assisting in normal nerve function, especially learning and memory.” If we’re going to have ‘pill solves complex social problem‘ stories, people could at least be clear as to what is in the pills.

Durham fish oil (non)trial: confusing numbers, and the dangers of science by press release

If I didn’t know better, I might suspect that Durham’s fish oil trial initiative has been designed as an example of the dangers of releasing scientific results via the mainstream media. I have been looking over the Durham figures, and the situation is so bad that there is even some confusion as to how many students were eligible to start on the trial and how many took the pills.

The fish oil zombie swims again in Durham: the fabulous mutating press release

In a fine example of convergent evolution, some information posted on HolfordWatch, the digging by Letting off Steam and Ben Goldacre’s tenacity have a welcome airing as the Durham fish oil zombie once again swims through the nutrient-rich waters of the Bad Science blog. This week, Ben Goldacre returns again to the Durham fish oil (non)trial:

And so an epic saga comes to a close. You will remember the Durham Fish Oil tale – don’t switch off now, the punchline’s funny. The county council said it was doing a “trial” of fish oil pills in children, but the trial was designed so that it couldn’t possibly give useful information – not least because it had no placebo group – and was very likely to give a false positive result.

However, we don’t feel that the story is over quite yet. There is still plenty of information to come out: although any hopes of meaningful results from this trial are long dead, the Durham fish oil zombie still swims this morning and will return to swim another day. For starters, we would like to tell you the story of the fabulous mutating press release to come out

Patrick Holford, Food for the Brain and Equazen

Professor Patrick Holford of Teesside University and Head of Science and Education at Biocare has an unerring sense for his endorsements (see, e.g., the qLink with the unconnected coil and the dLan that may enhance your exposure to EMR and YorkTest, the IgG food intolerance tests criticised by both the House of Lords and the ASA). Holford managed to procure some useful backing for the Food for the Brain project. One of the companies is Equazen. Equazen donated essential fat supplements to school projects. With an astonishing sense of inevitability, Equazen has just been criticised by the ASA and found to be unable to substantiate some of its advertising claims: e.g. “A Hi-EPA fish oil formula that may help maintain concentration levels and healthy brain development”.

NICE recommendations for fish oil after a heart attack

In the Irish Independent, Holford is quoted as stating that “The UK’s National Institute of Clinical Excellence [NICE] recommends that all doctors prescribe one gram of fish oil to patients who have had a heart attack. The trouble is, most of us don’t eat nearly enough omega 3 and 6 fats.” However, NICE actually recommend [PDF, p.5] that patients “Eat two to four portions of oily fish a week, such as herring, sardines,mackerel, salmon, trout and tuna.,,,If you have had a heart attack in the last 3 months and do not eat enough oily fish, your doctor may offer a medicine to supplement your diet.”

In other words: eat oily fish, it’s tasty and healthy. If eating enough fish is a problem, then your doctor may suggest supplements (and, obviously, do not stop taking a prescribed supplement due to a blog post). One more thing – most people eating a ‘Western diet’ will consume too high a ratio of omega 6 fats to omega 3 fats. However, if you do feel that you are deficient in omega 6 fats, these can easily be topped up with things like sunflower seeds and oil.