New evidence has emerged about a possible link between artificial additives in food and hyperactive behaviour in children.
UK government food advisers immediately tightened its dietary advice after the biggest study of its kind to date found normal children given a cocktail of additives behaved impulsively and lost concentration.
The Food Safety Authority of Ireland followed suit, saying parents of children in Ireland who display symptoms of hyperactivity or of Attention Deficit Hyperactivity Disorder (ADHD) "should consider limiting their children's consumption of food products containing these food colours".
The FSAI recommended "that parents read food labels when buying products so that they can identify if they contain these food colours and thus make an informed purchasing decision".
Tests in the UK's Food Standards Agency (FSA)-commissioned study on more than 300 children showed significant differences in their behaviour when they drank fruit drinks containing a mixture of food colourings and preservatives, Prof Jim Stevenson and colleagues at the University of Southampton said.
"These findings show that adverse effects are not just seen in children with extreme hyperactivity (such as ADHD) but can also be seen in the general population and across the range of severities of hyperactivity," the researchers wrote in their study, published in the Lancetmedical journal.
The additives included sunset yellow colouring, also known as E110; carmoisine, or E122; tartrazine, or E102; ponceau 4R, or E124; the preservative sodium benzoate, or E211; and other colours.
One of the two mixtures contained ingredients commonly drunk by young children in popular drinks, they said. They did not specify what foods might include the additives.
Following publication of the report, the FSA urged parents of children with hyperactive disorders to stop giving them food containing the artificial colours used in the tests.