Additives in sweets and soft drinks made by multinational companies have been found to cause hyperactivity in children, prompting renewed calls for a ban on E-numbers.
Primary school children tested by Southampton University were more restless when they drank a mixture of six colourings and one preservative.
Last night the Food Standards Agency, which funded the three-year follow-up to an earlier study, rejected calls for a ban on the additives. Instead, the regulator advised parents to avoid the ingredients if their children showed signs of hyperactivity.
The study strengthens a link between additives and behavioural difficulties first mooted in the 1970s, but establishes for the first time that they cause hyperactivity among normal infants. In the study, published in the Lancet today, 153 three-year-olds and 144 eight-year-olds in Southampton were randomly given daily fruit juice drinks, some containing additives and some containing a placebo.
The chemicals used were two combinations of the colourings sunset yellow (E110),tartrazine (E102), carmoisine (E122) ponceau 4R (E124), allura red (E129), quinoline yellow (E104), and the preservative sodium benzoate (E211). (Soft drinks containing the preservative E211 include Pepsi Max, Fanta, Sprite and Dr Pepper, while the other E-numbers are to be found in many sweets and cakes.)
After drinking them, the younger children were monitored by parents, teachers and trained observers, while the older children also sat a computer hyperactivity test.
Both drinks given to both age groups had a greater effect than the placebo, though in one of the four groups the change was just below statistical significance. All four groups showed higher signs of hyperactivity, switching activities, interrupting or talking too much, and fiddling with objects or their own body. On average, children exhibited about 10 per cent of the level of symptoms of children with attention deficit hyperactivity disorder (ADHD).
In the Lancet, Professor Jim Stevenson, who led the study, wrote: "The present findings, in combination with the replicated evidence for the artificial food colour and additives effects on the behaviour of three-year-old children, lent strong support for the case that food additives exacerbate hyperactive behaviours."
The FSA has held talks with the food industry, which has been slowly withdrawing additives in recent years. The food regulator said it issued its advice after consulting the independent committee on toxicity, which decided that the effects were not so widespread they posed a threat to the general population.
Dr Andrew Wadge, the FSA's chief scientist, said: "If a child shows signs of hyperactivity or ADHD, then eliminating the colours used in the Southampton study from their diet might have some beneficial effects."
He added: "However, we need to remember that there are many factors associated with hyperactive behaviour in children. These are thought to include genetic factors, being born prematurely, or environment and upbringing."
Dr Alex Richardson, an Oxford University academic who is director of the Food and Behaviour Research charity, said the £750,000 study confirmed the dangers of many additives.
She said: "The key thing is that the effects they have found are not confined to a sub-group of children. That being the case, you might have thought that all children should be minimising their consumption of such additives. It seems a bit odd to me that only if parents notice children are being hyperactive they might cut down. It's a bit like saying: 'Well, we'll wait until you get the heart attack...' "
Maynards Wine Gums: E104, E122, E129
Pepsi Max: Sodium Benzoate (E211)
Haribo Star Mix: E104, E110, E124
Hubba Bubba Bubble Tape (Snappy Strawberry flavour): E129
Flumps: E104, E129
Oasis Summer Fruits: E122 and sodium benzoate (E211)
Gourmet jelly beans: E102, E110, E129
Fruit salad bar (Barratt): E104, E124, E122
The Simpsons peach water: H2O Sodium benzoate (E211)