Clinical trial links attention deficit/hyperactivity behaviors to blend of artificial food preservative and colors
by Craig Weatherby
Attention deficit hyperactivity disorder (ADHD) can take quite a toll on kids, caregivers, and teachers.
And the widespread prescription of stimulant-type ADHD drugs like Ritalin for children, whose brains are still forming, makes many parents and resarchers nervous.
So parents' ears prick up at the hint of anything that might alleviate ADHD without resort to controversial pharmaceuticals.
We've reported on research indicating that omega-3s may help some children with ADHD.
A new study suggests that there may be substance to some parents' claims that their kids' ADHD is triggered or exacerbated by food additives.
While it is widely held, the belief that food additives promote attention-hyperactivity deficits in children is scientifically controversial. As the authors of two recent evidence reviews said:
- “…to date, there is little empirical evidence supporting the effectiveness of dietary restrictions in treating… attention deficit hyperactivity disorder (ADHD)” (Cormier E, Elder JH 2007).
- “…a critical review of the literature provides very limited support for such a relationship [between food additives and ADHD]” (Cruz NV, Bahna SL 2006).
But the results of a very credible new clinical trial lend weight to parents' concerns about synthetic chemicals in foods.
New results find fault with common additives
Scientists at University of Southampton in England conducted a well-designed clinical trial—randomized, double-blind, placebo-controlled, crossover—intended to test whether intake of artificial food color and additives (AFCA) would affect children's behavior.
They enrolled 153 three-year-olds and 144 children aged eight to nine years of age, separated them into three groups, and gave each group a different drink:
- Test Drink A with sodium benzoate (preservative) and artificial food color mix A.
- Test Drink B with sodium benzoate (preservative) and artificial food color mix B.
- Placebo drink free of artificial additives and preservatives.
Each group consumed their beverage daily for six weeks. The researchers estimated that the test drink groups ingested artificial additives and preservatives in daily amounts roughly equal to those found in two standard candy bars.
In addition to a computer test, the children were evaluated by parents and/or teachers who were unaware of which drinks the children had consumed.
The researchers found that children of all ages who consumed Test Drink A were significantly more hyperactive and that they had shorter attention spans, compared with the placebo drink groups.
No behavior differences were found between the placebo group and Test Drink B group.
The authors came to this conclusion: “Artificial colors or a sodium benzoate preservative (or both) in the diet result in increased hyperactivity in 3-year-old and 8/9-year-old children...”
Since all the children received a mix of additives, the authors could not say which of the additives caused problems, but they plan to conduct further trials to pinpoint the problematic compounds.
- McCann D, Barrett A, Cooper A, Crumpler D, Dalen L, Grimshaw K, Kitchin E, Lok K, Porteous L, Prince E, Sonuga-Barke E, Warner JO, Stevenson J. 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. Lancet. 2007 Sep 5; [Epub ahead of print]
- Cormier E, Elder JH. Diet and child behavior problems: fact or fiction? Pediatr Nurs. 2007 Mar-Apr;33(2):138-43. Review.
- Cruz NV, Bahna SL. Do food or additives cause behavior disorders? Pediatr Ann. 2006 Oct;35(10):744-5, 748-54. Review.