A study by researchers at the University of Southampton has linked increased levels of hyperactivity in young children consuming mixtures of some artificial food colours and the preservative sodium benzoate.

The research, funded by the UK’s Food Standards Agency (FSA), involved studying levels of hyperactivity in 153 three-year-olds and 144 eight-year-olds living in the city of Southampton. The children whose parents volunteered their participation, were selected to represent the full range of behaviour, from normal through to hyperactive.

The children's families were asked to put them on a diet free from the additives used in the study. Over a six-week period the children were then given a drink each day which either contained one of two mixtures of food colours and benzoate preservative, or just fruit juice.

The research team used a combination of reports on the children's behaviour from teachers and parents, together with recordings of the children's behaviour in the classroom made by an observer, and, for the older children, a computer-based test of attention. None of the participants - teachers, parents, the observer, or the children - knew which drink each child was taking at any one time.

The results of the Southampton study show that when the children were given the drinks containing the test mixtures, in some cases their behaviour was significantly more hyperactive. These results replicate and extend previous FSA-funded research by the team in Southampton.

Professor of Psychology, Jim Stevenson, who led the research, also notes '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.'

Further reading: The Lancet