Cutting out colours and preservatives from the diets of hyperactive children should be standard part of dealing with the disorder, says a professor who takes a more stringent view than the FSA following the Southampton study publication.
Certain artificial colours and the preservative sodium benzoate have been under the spotlight in the last year since a study conducted at Southampton University and funded by the UK's Food Standards Agency (FSA) found an adverse link between certain cocktails of additives and behaviour in children drawn from the general population.
In its initial advice following the study's publication in The Lancet, the FSA issued mildly worded advice to parents - that eliminating the suspect additives from the diet could have some benefits for hyperactive kids or those with ADHD.
A media storm ensued, and the latest word from the FSA is that it will push for the additives to be phased out.
However Professor Andrew Kemp of the University of Sydney writes in the British Medical Journal that removing additives from the diet of children with ADHD, in a properly supervised trial, should not be considered an alternative treatment.
At present, there are three main approaches to tackling ADHD: drugs, behavioural therapy, and dietary management.
He said that 2.4 per cent of children in Western Australia take drugs for hyperactivity - yet in contrast, he considers the dietary approach to be "relatively harmless".
In addition, some 50 per cent of children attending tertiary hospitals for children in the UK and Australia in the last 12 months have used alternative medicine, such as behavioural therapy.
Indeed, behavioural therapy is still considered necessary for 'adequate treatment' - even though there is less evidence for its efficacy than there is for eliminating food additives.
The European Food Safety Authority (EFSA) conducted a review of the Southampton study, as well as other studies and meta-analyses on additives and hyperactivity conducted between 1975 and 1994.
EFSA's take, however, is that hyperactivity stems from a variety of social and biological causes, and focusing on good additives alone may "detract from the provision of adequate treatment".
Professor Kemp countered: "It could be said that neglecting the substantial body of evidence on dietary factors may also do this."
EFSA also concluded that the Southampton study gave no basis for changing acceptable daily intakes (ADI) of food additives.
Part of the reason is that the 297 children participating in the trial were given cocktails of additives, so the data make it impossible to ascertain which one(s) are responsible for the hyperactivity effect.
The Southampton study
The study conducted in two phases. In stage one, 153 three-year olds and 144 eight- and nine-year olds were given one of two drink mixes containing artificial food colours and additives, or a placebo. The children were drawn from general population and across a range of hyperactivity and ADHD (attention deficit hyperactivity disorder) severities.
Mix A contained sunset yellow (E110), tartrazine (E102), carmoisine (E122), ponceau 4R (E124) and sodium benzoate (E110). This same mix was used in an earlier study on a cohort of three-year-olds which was deemed inconclusive because the effects were not confirmed by clinicians.
Mix B contained sunset yellow (E110), quinoline yellow (E104), carmoisine (E122), allura red (E129) and sodium benzoate (E110).
Phase one lasted six weeks, and every child consuming the mixes and the placebo for one week each, with a one week wash-out period between each. Parents were asked to keep other sources of artificial colours out of the diet, and to keep a diary of violations.
Phase two involved some of the children from the older group - responders and non-responders - during two half-day session a week apart, at which they were given either a placebo or an active drink similar to mix A or B, but the whole day's dose was given at once.
The conclusions drawn by the researchers were that artificial food colours and additives were seen to exacerbate hyperactive behaviour in children at least up to middle childhood.
British Medical Journal 2008; 336:1144
"Food additives and hyperactivity"
Author: Kemp, A
The Lancet 2007; 370:1560-70
"Food additives and hyperactive behaviour in 3-year-old and 8/9 year-old children in the community a randomised, double-blinded, placebo-controlled trial"
Authors: McCann D, Barrett A, Cooper A, Crumpler D, Dalen L, Grimshaw K, et al