Food Additives, ADHD and Hyperactivity

Attention Deficit Hyperactivity Disorder (ADHD) is a psychiatric disorder that is estimated to affect 1-5% of children and 5% of adults. Symptoms include acting on impulse without thinking about the consequences. This could include shouting out to get someone's attention or running about when it is not appropriate. People with ADHD have a short attention span and excessive, almost uncontrollable activity (hyperactivity). The symptoms of ADHD can range from mild to severe and people with the disorder often suffer from other psychological problems.

Photo of brain scan

Brain scan
Picture courtesy: University of Alabama at Birmingham, Department of Radiology©

Southampton University Research

In 2007, results from the University of Southampton suggested that there was a link between increased activity in children and certain food colourings and the preservative sodium benzoate. The study looked at over 260 children in two age groups; three and eight to nine year olds. They used a 'double-blind, placebo controlled' experiment. The diagram below shows what that means! (click here for text description)

Diagram of experiment

So what is the answer?

Scientists are still cautious about the results. The Food Standards Agency (FSA) now advises parents of children who already show signs of hyperactivity to avoid foods containing certain food colourings. This may help with their children's behaviour.

Even though the research does not show that artificial colours are the cause of hyperactivity, these colours are increasingly being replaced in foods by natural ones such as beta-carotene. Also, by law, all additives must be listed on the label and so foods that contain artificial colours can easily be identified.

The European Food Safety Authority (EFSA) looked at the Southampton University research and decided that the results were not clear cut. EFSA were not convinced that the small alterations in attention and activity that were observed in the study would actually interfere with children's ability to think and perform schoolwork.

EFSA therefore decided that no change was necessary to the current acceptable daily intake of these food colours and sodium benzoate.

The UK Food Standards Agency (FSA) has taken a slightly different view and called for a Europe-wide ban on the colours. This is unlikely to happen as there is no support from the European agency for a ban. The FSA have therefore asked UK food producers to voluntarily withdraw use of the these colours by 2009.

Photo of glass of orange juice

Some parents are concerned about colourings added to drinks