UK researchers believe they have demonstrated a link between certain artificial food additives and colourings used in soft drinks and hyperactivity in children.

The study, led by Jim Stevenson at the University of Southampton, carried out tests on more than 300 children in two groups, one comprising three-year-olds and the other eight- and nine-year-olds. Researchers said it showed significant differences in the behaviour of children who had drunk fruit drinks containing a mixture of food colourings and preservatives.

"These findings show that adverse effects are not just seen in children with extreme hyperactivity, such as Attention-Deficit/Hyperactivity Disorder (ADHD), but can also be seen in the general population and across the range of severities of hyperactivity," the researchers wrote in the study which was published in the UK medical journal The Lancet yesterday (4 Sept).

Among the colourings and additives given to the children were sunset yellow colouring, also known as E110; carmoisine, or E122; tartrazine, or E102; ponceau 4R, or E124; the preservative sodium benzoate, or E211.

The research adds further to the debate over the use of artificial additives and will be seized upon by pressure groups seeking to tighten regulations on the use of such ingredients. But UK trade organisation the Food and Drink Federation (FDF) said the study did not raise safety issues for drinks companies.

"Manufacturers are very aware of consumer sensitivities about the use of additives in food and drink products," said Julian Hunt, director of communications at the FDF.

"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."

"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."

Hunt added that as manufacturers are legally obliged to label which additives they use in their products, consumers wishing to avoid certain ingredients can do so.

While some experts said they believed the study was very significant, others remained less convinced.

Dr Sue Baic, a dietitian at the University of Bristol, said: "This is a well designed and potentially very important study. It supports what dietitians have known for a long time, that feeding children on diets largely consisting of heavily processed foods which may also be high in fat, salt or sugar is not optimal for health."

However, toxicologist and food safety consultant Dr Paul Illing, said: "The paper shows some statistical associations. It is not a demonstration of cause and effect."