Parents are being warned of a link between disruptive behaviour and hyperactivity in children and certain food additives.
Research conducted by the Food Standards Agency established that children behave impulsively, and lost concentration after drinking a cocktail of additives and preservatives. Some 300 children were involved in the study, which was carried out at the University of Southampton.
The children, aged from three to nine years, were given a drink containing four artificial colours (sunset yellow (E110), quinoline yellow (E104), carmoisine (E122), allura red (E129)) and the preservative sodium benzoate (E211). The mix was designed to reflect the composition and quantity of additives a child was likely to consume in a typical day.
They were also given another mix, identical to that in a previous study. This contained E102 (tartrazine) and E124 (Ponceau 4R), as well as sunset yellow, carmoisine and sodium benzoate. There was also a placebo, containing no additives at all.
After the drink, some, but not all of the children showed signs of hyperactivity. The response was not limited to those participants already identified as being hyperactive.
The researchers said that based on the two mixes the children consumed, they couldn't specify which of the chemicals was the trigger for deteriorating behaviour. But as sodium benzoate was in both mixes, and the results were inconsistent, it was likely to be one of the food colourings.
Dr Andrew Wadge, the FSA's chief scientist, said: "We have revised our advice to consumers: if a child shows signs of hyperactivity or ADHD, then eliminating the colours used in the study from their diet might have some beneficial effects."
There are many other factors thought to contribute to hyperactivity, and the researchers stressed that there was no suggestion that eliminating additives will be a panacea for the disorder.
The agency has also passed its findings onto its European counterparts, the European Food Safety Authority, which will now decide whether or not to update European safety guidelines.
But critics say the government has not gone far enough. Professor Jim Stevenson, who headed the Southampton study, told The Guardian that his personal view was that the government could easily take a tougher stance, and ban the chemicals used in the study.
Meanwhile, the Hyperactive Children's Support Group told the paper that while it welcomed confirmation of the link, it questioned the practicality of the advice. Is it practical, it asked, to expect parents to interrogate schools about their meals, or friends about the contents of party bags?
Others advise caution in extrapolating from such a small study to the wider population.
You can read more on the research here. The work is published in The Lancet. ®