Some Food Additives Raise Hyperactivity,
Study Finds By ELISABETH ROSENTHAL
Published: September 6, 2007, The New York Times
Common food additives and colorings can increase hyperactive
behavior in a broad range of children, a study being released today
found.
It was the first time researchers conclusively and scientifically
confirmed a link that had long been suspected by many parents.
Numerous support groups for attention deficit hyperactivity disorder
have for years recommended removing such ingredients from diets,
although experts have continued to debate the evidence.
But the new, carefully controlled study shows that some artificial
additives increase hyperactivity and decrease attention span in a
wide range of children, not just those for whom overactivity has
been diagnosed as a learning problem.
The new research, which was financed by Britain’s Food Standards
Agency and published online by the British medical journal The
Lancet, presents regulators with a number of issues: Should foods
containing preservatives and artificial colors carry warning labels?
Should some additives be prohibited entirely? Should school
cafeterias remove foods with additives?
After all, the researchers note that overactivity makes learning
more difficult for children.
“A mix of additives commonly found in children’s foods increases the
mean level of hyperactivity,” wrote the researchers, led by Jim
Stevenson, a professor of psychology at the University of
Southampton. “The finding lends strong support for the case that
food additives exacerbate hyperactive behaviors (inattention,
impulsivity and overactivity) at least into middle childhood.”
In response to the study, the Food Standards Agency advised parents
to monitor their children’s activity and, if they noted a marked
change with food containing additives, to adjust their diets
accordingly, eliminating artificial colors and preservatives.
But Professor Stevenson said it was premature to go further. “We’ve
set up an issue that needs more exploration,” he said in a telephone
interview.
In response to the study, some pediatricians cautioned that a diet
without artificial colors and preservatives might cause other
problems for children.
“Even if it shows some increase in hyperactivity, is it clinically
significant and does it impact the child’s life?” said Dr. Thomas
Spencer, a specialist in Pediatric Psychopharmacology at
Massachusetts General Hospital.
“Is it powerful enough that you want to ostracize your kid? It is
very socially impacting if children can’t eat the things that their
friends do.”
Still, Dr. Spencer called the advice of the British food agency
“sensible,” noting that some children may be “supersensitive to
additives” just as some people are more sensitive to caffeine.
The Lancet study focused on a variety of food colorings and on
sodium benzoate, a common preservative. The researchers note that
removing this preservative from food could cause problems in itself
by increasing spoilage. In the six-week trial, researchers gave a
randomly selected group of several hundred 3-year-olds and of 8- and
9-year-olds drinks with additives — colors and sodium benzoate —
that mimicked the mix in children’s drinks that are commercially
available. The dose of additives consumed was equivalent to that in
one or two servings of candy a day, the researchers said. Their diet
was otherwise controlled to avoid other sources of the additives.
A control group was given an additive-free placebo drink that looked
and tasted the same.
All of the children were evaluated for inattention and hyperactivity
by parents, teachers (for school-age children) and through a
computer test. Neither the researchers nor the subject knew which
drink any of the children had consumed.
The researchers discovered that children in both age groups were
significantly more hyperactive and that they had shorter attention
spans if they had consumed the drink containing the additives. The
study did not try to link specific consumption with specific
behaviors. The study’s authors noted that other research suggested
that the hyperactivity could increase in as little as an hour after
artificial additives were consumed.
The Lancet study could not determine which of the additives caused
the poor performances because all the children received a mix. “This
was a very complicated study, and it will take an even more
complicated study to figure out which components caused the effect,”
Professor Stevenson said.
