Whether preservatives and colourings cause or exacerbate hyperactive behaviours is an important question for many paediatricians and parents. A recent randomised placebo controlled trial in 297 children aged 3-9 years provides evidence of increased hyperactive behaviour after they ate a mixture of food colourings and a preservative (sodium benzoate).1 In contrast to many previous studies, the children were from the general population and did not have attention-deficit/hyperactivity disorder. The trial found an adverse effect of the mixture on behaviour as measured by a global hyperactivity aggregate score. The daily dose approximated that found in two 56 g bags of sweets.

In view of the potential importance of these findings, the European Food Safety Authority (EFSA) recently provided an opinion that takes other evidence into account. …