PARENTS were warned today of the dangers of artificial additives in drinks, sweets and processed foods after new evidence emerged about a possible link to hyperactive behaviour in children.

The Government's food advisers immediately hardened their dietary advice after the biggest study of its kind to date found normal children given a cocktail of additives behaved impulsively and lost concentration.

But food safety campaigners urged the Government to go further and put legal limits on additives in food.

Psychology Professor Jim Stevenson, who led the FSA -commissioned study, said: "We now have clear evidence that mixtures of certain food colours and benzoate preservative can adversely influence the behaviour of children.

"There is some previous evidence that some children with behavioural disorders could benefit from the removal of certain food colours from their diet.

"We have now shown that for a large group of children in the general population, consumption of certain mixtures of artificial food colours and benzoate preservative can influence their hyperactive behaviour.

"However, parents should not think that simply taking these additives out of food will prevent all hyperactive disorders.

"We know that many other influences are at work but this at least is one a child can avoid."

Hyperactive

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.

Dr Andrew Wadge, the FSA's Chief Scientist, said the agency acted after its expert Committee on Toxicity (COT) reported on the study.

He said: "After considering the COT's opinion on the research findings we have revised our advice to consumers: 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."

"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."

But the Soil Association said the FSA's response was "totally inadequate" and urged it to take tougher action.

Spokeswoman Emma Hockridge said: "The FSA should be taking a leading role in addressing this issue in light of this new research, and undertaking initiatives to prevent the development of hyperactive disorders, through new policies to limit food additives."

A spokesman for campaign group The Food Commission said food manufacturers should "clean up their act" by voluntarily removing the additives from their products.

He said: "These artificial colourings may brighten up processed foods and drinks but it appears they have the potential to play havoc with some children's behaviour.

Scientists from Southampton University gave test groups of three and eight and nine year-olds a mixture of additives found in average daily diets and measured their reactions.

The children, chosen as a snapshot of the general population, were first tested on additive-free diets and none were hyperactive.

Every day for six weeks they were then given drinks which either contained one of two mixtures of food colours and benzoate preservative or just fruit juice. All the drinks looked and tasted the same.

The children's different reactions were rated by teachers and trained observers in the classroom and by their parents at home. The older children also took computerised attention tests.

The FSA will now send the findings to the European Food Safety Authority , which is reviewing the safety of all EU permitted food colours.

A food and drink industry representative said the way the additives were tested was not the same as they were used in everyday products.

Safety

Julian Hunt of the Food and Drink Federation said: "It is important to reassure consumers that the Southampton study does not suggest there is a safety issue with the use of these additives.

"In addition, the way in which the additives were tested as a mixture is not how they are used in everyday products.

"As a responsible industry, we shall be studying the detail of the research and companies will clearly take account of these findings as part of their ongoing review of product formulations.

"The industry continues to respond to consumer demand by reducing the use of additives and there are many food and drink products on supermarket shelves that contain no artificial colours."