Parents have been warned to avoid artificial additives used in drinks, sweets and processed foods amid a link to behaviour problems in children.
A study funded by the government’s Food Standards Agency(FSA) is understood to have drawn a link with temper tantrums and poor concentration.
There are also concerns about allergic reactions such as asthma and rashes.
The findings are potentially explosive for the entire food industry, which faces the need to reformulate a vast array of children’s products.
Vyvyan Howard, professor of bio-imaging at Ulster University and an adviser to the FSA, called on parents and manufacturers to protect children.
He said: “It is biologically plausible that they could be having an effect.
“Parents can protect their children by avoiding foods containing the additives. I personally do not feed these sorts of foods to my 15-month-old daughter.”
He called on manufacturers and supermarkets to remove the additives on a precautionary basis.
He said: “It is the right thing to do to remove these additives from children’s foods. They have no nutritional value, so why put them in?
“There are very tight restrictions banning these additives from foods designed for children under the age of one.
“But why stop there? Children’s brains and nervous systems are developing beyond the age of one.”
Prof Howard is not a member of the FSA committee assessing the latest research, however he did advise on how the study should be conducted.
Experts on the FSA’s Committee on Toxicity(CoT) are expected to say that parents who want to minimise any risk of an adverse reaction should avoid these additives.
Some leading companies have already responded to mounting evidence of harm caused by chemical additives, particularly the vivid colours used to dress up products.
Smarties has dropped artificial colours with the result the blue variety has been axed.
Sainsbury’s recently announced a ban on artificial colours and flavours from 120 own label soft drinks. This follows similar moves by Marks & Spencer and the Co-op.
The research, carried out by a team from Southampton University, appears to confirm earlier studies suggesting additives can cause reactions, either individually or as a cocktail.
The colours, tested on groups of three-year-olds and eight-to-nine year olds, were tartrazine (E102), ponceau 4R (E124), sunset yellow (E110), carmoisine (E122), quinoline yellow (E104) and allura red AC (E129).
The team also looked at the effect of the preservative sodium benzoate (E211), which is commonly used in soft drinks.
Precise details of the research findings are being kept secret until they can be peer reviewed and published in a scientific journal.
However, a source at Southampton University told the food industry’s magazine, The Grocer, that their results are in line with earlier findings, published in 2004.
The original research, which took place on the Isle of Wight, involved giving fruit drinks to children aged three. In some weeks, these were laced with additives.
Parents reported changed behaviour when the youngsters were given the additives.
However, the original findings were questioned because they relied on anecdotal reports from parents while the fact the children were so young made it difficult to measure their behaviour in a meaningful way.
Because of these doubts, a second tranche of research was commissioned following advice from an expert committee, which included Professor Howard.
The Founder of the Hyperactive Children Support Group, Sally Bunday, said there is good evidence that artificial additives can have a harmful effect.
She said: “The consequences can be very serious for both children and adults who are sensitive to these artificial colours.
“The reaction in children can be horrendous in terms of mood swings with crying, screaming, inability to sleep. There can also be physical reactions such as difficulty in breathing on skin rashes.
“For a young person there is also a risk of quite angry mood swings.”
The founder of the organic brand Organix, Lizzie Vann, has been campaigning for a ban on all artificial additives from children’s food.
“The use of artificial additives in children’s foods means we are conducting a long-term experiment on our children’s health,” she said.
“If the Government is serious about improving children’s nutrition the ban on artificial food additives must be a priority.”
The Food & Drink Federation, which speaks for manufacturers, said the colours and chemicals used by the industry are proven to be safe.
“The use of food additives is strictly regulated under European law,” it said.
“They must be approved as safe by the appropriate European scientific committee before they can be used…Consumers’ intake of food additives is also closely monitored.
“A recent European Commission report on ‘Dietary Food Additive Intake’ indicated that consumption of all types of additives was within the strict safety limits set by the legislation. Particular attention was given to consumption by children.”
The FSA and Southampton University refused to comment until the research has been officially published.