The Food Standards Agency (FSA) faces tough questions over its involvement in a prominent study into additives and hyperactivity that EU food safety watchdogs claim was poorly designed with unclear results.
The FSA-financed University of Southampton study showed children given drinks containing combinations of artificial colours and preservative sodium benzoate became more hyperactive than those in control groups.
However, as predicted by toxicological experts (FM, October 2007, p4), this did not help the European Food Safety Authority (EFSA) decide which, if any, of the colours to ban, because it failed to isolate which additives were responsible for the changes in behaviour.
"Since mixtures and not individual additives were tested it is not possible to ascribe the observed effects to any of the individual compounds," said EFSA. "The clinical significance of the observed effects also remains unclear, since it is not known whether small alterations in attention and activity would interfere with schoolwork and other intellectual functioning."
But the colours were not off the hook yet, said an EFSA spokesman. "This study was just one piece of evidence we were asked to look at as part of our review of additives."
Professor Jim Stevenson, who led the study, insisted he had "never claimed to be able to isolate the effects of individual additives"; adding: "The study - as commissioned by the FSA - was designed to test two mixtures."
The "most obvious next step" was to test the effects of sodium benzoate alone, he said. "But we do not at present have any funds for further research." The FSA declined to comment, although industry sources confirmed it had approved the study design before agreeing to fund it.
The Hyperactive Children's Support Group (HACSG) lamented a lack of wider research. HACSG trustee Griselda Halling referred to "63 further additives which our research has associated with behavioural changes in children". She added: "Sadly the FSA has no plans to fund further research."