Making the link: food additives and hyperactivity

Artificial food colourings that have an adverse effect on children's behaviour have been phased out by UK manufacturers thanks to a Southampton study which showed a link between certain food additives and hyperactivity in children.

The possibility that food colours and preservatives might affect the way children behave had long been an unresolved question for parents. The research findings, published in 2007, demonstrated a clear link between changes in children's behaviour and their intake of a number of food colourings and one preservative, sodium benzoate.

Professor Jim Stevenson, who led the research, comments: "Our study has made an important contribution to improving children's health. We have shown that food additives were having a detrimental effect in the general population, not just in a group with a high level of hyperactivity."

In response to the study, the government's Food Standards Agency, which protects the public's health and consumer interests in relation to food, asked UK manufacturers to phase out the six food colourings by the end of 2009. It also recommended further investigation into the effects of sodium benzoate. The findings also led to new European Union (EU) regulations that require additional warning information on most food and drink supplied to EU countries containing any of the six colourings.

The research involved studying levels of hyperactivity (behaviour characterised by increased movement, impulsiveness and problems with concentration) in 153 three-year-olds and 144 eight-year-olds living in Southampton using a rigorously controlled trial design. The children were chosen from the general population 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. The drinks looked identical, but either contained one of two mixtures of food colours and the preservative, or just fruit juice. Parents and children were not aware of which they were taking at which time.

The results showed that when the children were given the drinks containing the test mixtures, in some cases their behaviour was significantly more hyperactive.