by Stephen Pincock
Like many other people with young children, I watched chef Jamie Oliver's new television series about school dinners with the kind of horrified fascination that train wrecks can engender.
The shocking state of canteen food highlighted by the programme has rightly prompted national debate in the UK. Children simply cannot grow up healthy if they're allowed to eat a daily supply of chips, frozen pizza and grotesque meat-based products - a fact that's all the more pertinent in this age of obesity.
But part of the reason that Oliver's campaign has prompted such a reaction is, I think, down to another diet-related issue. Fascination with the link between nutrition and behaviour in children has reached a fever pitch among many parents.
In one episode of the programme, the parents of a gaggle of tearaway kids were instructed by Oliver to cut out junk foods, fizzy drinks and sweets and replace them with healthier alternatives. Interviewed a couple of weeks later, they said they had noticed an amazing difference in behaviour--one that reversed itself almost instantly when they caved in and allowed the children a "treat" meal of processed food and soft drink.
But from a scientific perspective there's a world of difference between anecdote and solid evidence. Parents who actively decide to alter their children's diet are more likely to see a behaviour change, because that's what they want to see. So, how strong is the evidence? In short, its already more than suggestive and growing stronger.
Take artificial colourings and other "E" numbers, for example, which have been in the bad books for ages now. Last year came the publication of best evidence to date supporting the idea that cutting them out of a child's diet can result in significant improvements in problems.
In a study sponsored by the UK government, Professor John Warner and colleagues studied 277 three-year-olds on the Isle of Wight, and categorized them into four groups--those with allergy, those with signs of attention deficit hyperactivity disorder (ADHD), children with both and those with neither.
The children were all put on a diet that eliminated artificial food colourings and benzoate preservatives. The researchers then supplemented the diet with a fruit drink that either did or did not contain the artificial junk. The children's behaviour was assessed by parents and by an outside observer, neither of whom knew which drink the kid was drinking.
The study found significant reductions in hyperactive behaviour when the children were not getting the additives, and increases in hyperactivity when they were. "It wasn't just a sub-group of children who were affected, it was across the board," says Dr. Alex Richardson, of Oxford University, a high profile researcher in the field.
Richardson herself is the senior investigator in a study looking at the latest hot-button subject in diet and behaviour, fish oils--which many parents will tell you can transform the behaviour of a "problem" child.
Fish oils are high in omega 3 fatty acids, which are known to be important for brain development, hormonal balance and the immune system, but which many modern diets lack. There are even suggestions that the evolution of humans' cognitive function is linked to fish eating.
The scientific evidence of the benefits of fish oil supplements is so far not conclusive. But it's about to get a boost, as a largish study conducted by Richardson and colleagues in children has now been accepted for publication in a scientific journal.
The study has been getting some premature media coverage, perhaps unsurprisingly. "We get a huge amount of interest," Richardson told me last week. "It's mostly the parents and also teachers who are interested in whether diet affects behaviour."
The study looked at children classified as "dyspraxic," meaning they had problems with physical coordination, "dyslexic" (problems with reading) and with ADHD.
Because the results have not yet been published, Richardson won't divulge the full outcome yet. But she would say that giving the children a daily fish oil supplement containing half a gram of omega three fatty acids resulted in significant improvements. "What we've shown is that you can improve behaviour and learning with these oils," she said.
It's not the first study to show dramatic improvements in behaviour with dietary supplements. As long ago as 2002, for example, researchers studying teens in a young offenders institution found that dietary changes could reduce violence.
The researchers looked at the effects of supplemental fatty acids, minerals and vitamins on the behaviour of 231 prisoners. They found striking results--antisocial behaviour dropped 35% among inmates who took the supplements for two weeks or more compared to those who didn't.
This evidence is compelling--so why hasn't more been done by government, schools or, for that matter, parents? It's a mystery, says Richardson: "Everyone's aware that a lousy diet is bad for your physical health but it has taken a lot longer for people to twig that the brain is also part of your body and is possibly the first place you would be likely to see an effect."
For our children's sake, we should pay more attention to the evidence.