E-numbers do harm children, research shows

Artificial colourings and preservatives in food and drink boost levels of hyperactivity in pre-school children and urgent consideration should be given to removing them, doctors will claim today.

Artificial colourings and preservatives in food and drink boost levels of hyperactivity in pre-school children and urgent consideration should be given to removing them, doctors will claim today.

The additives have a "significant" impact on the behaviour of ordinary children and their elimination would be in the long-term interests of public health, researchers from the University of Southampton say.

The proportion of children with high levels of hyperactivity was halved when the additives were removed, the researchers found.

The Food Standards Agency, which assessed the findings, is to fund a larger follow-up study, beginning in September and continuing for three years.

The impact of additives on the behaviour of young children has been disputed for a quarter of a century since the first claims that they caused fidgeting and inattention in vulnerable children were made in the 1970s.

Researchers have found it difficult to prove the effect of additives in a normal population of children because the additives are ubiquitous in the foods and drinks that they consume. Previous studies have focused on their impact on children already identified as hyperactive, on the assumption that they would be more vulnerable to the additives' effect.

Now doctors at Southampton University have carried out the first study of their impact on a normal child population. They selected 277 children aged between three and four on the Isle of Wight and fed them a carefully controlled diet over four weeks. During the first week, they ate a strictly additive-free diet, devoid of colourings such as tartrazine and sunset yellow and the preservative sodium benzoate.

In the second week, half the children were given a daily drink of fruit juice containing colourings and preservatives, while the other half were given the same drink minus the additives. The experiment was repeated in the third and fourth weeks and changes in the behaviour of the children were noted by their parents, who did not know which drink their child had received. The children were also given a series of tests by independent observers.

The results showed parents rated their child as significantly less hyperactive when the additives were removed and markedly more so when they were put back in. As a result the proportion with the highest level of hyperactivity fell from 15 per cent to 6 per cent, the authors say. However, the independent observers found no differences in the behaviour of the children when the additives were given or removed. The researchers say this may be because the tests they administered were too entertaining and they saw the children when they were at their best.

Parents, on the other hand, see their children when they are hungry and tired, quarrelling with siblings or causing disruption in the supermarket and are more likely to be sensitive to subtle changes in behaviour.

Professor John Warner of the department of child health at Southampton University, who led the study published in Archives of Child Health, said: "These findings suggest that significant changes in children's hyperactive behaviour could be produced by the removal of artificial colourings and sodium benzoate from their diet." Professor Warner said the doses of additives used in the study were "on the low side of normal," and the effects were felt across all the children, regardless of their sensitivity to allergy causing substances.

"We were surprised by the results because the effect was not just in one group. We showed there was an effect on perfectly normal children. If that is confirmed by further research then there is a public health issue."

THE ADDITIVES IN THE TEST

COLOURINGS

Tartrazine (E102): A synthetic yellow azo dye found in fruit squash, fizzy drinks, custard powder, ice cream, sweets, chewing gum, jam and yoghurt. Commonly used in UK but banned in Norway and Austria.

Sunset yellow (E110): Also a synthetic yellow azo dye which must be heat treated. Found in orange jelly and squash, swiss roll, apricot jam, hot chocolate mix, packet soups, canned fish. Banned in Norway and Finland.

Carmoisine (E122): A synthetic red azo dye which must be heat treated. Used in blancmange, marzipan, jams, sweets, brown sauce, yoghurts, jellies and cheesecake mixes. Banned in Japan, Norway, Sweden and the US.

Ponceau 4R (E124): Also known as Cochineal Red, a synthetic red azo dye used in dessert toppings, jelly, salami, seafood dressings, tinned strawberries and fruit pie fillings. Banned in Norway and the US.

PRESERVATIVES

Sodium Benzoate (E211): The sodium salt of benzoic acid used as a food preservative and antiseptic. Found in margarine, pineapple juice, prawns, milk products, baked goods, lollipops and soft drinks.