The question of whether food additives such as preservatives,
artificial flavorings, and artificial colorings trigger hyperactivity
has been debated for more than 30 years. Research generally has not
supported food additives as influencing hyperactivity—whose
characteristics include overactivity, inattention, and impulsive
behaviors, traits that in extreme forms define attention
deficit/hyperactivity disorder (ADHD)—but some studies have found small
effects. Most recently, a study published 3 November 2007 in
suggests that the preservative sodium benzoate and commonly used
artificial food colorings in fact may exacerbate hyperactive behavior
in young children.
Lancet study, researchers
led by Jim Stevenson, a professor of psychology at the University of
Southampton, United Kingdom, built upon a previous double-blind
placebo-controlled study of preschool children. In that study,
published in the June 2004
Archives of Disease in Childhood,
3-year-old children on a diet free of artificial dyes and benzoate
preservatives exhibited increased hyperactivity when challenged with a
drink containing a mixture of the widely used sodium benzoate plus the
dyes Sunset Yellow, carmoisine, tartrazine, and Ponceau 4R (in their
later paper, Stevenson and colleagues termed this combination "mix A").
Again using a double-blind placebo-controlled design, the Southampton
team expanded the study group to include 153 3-year-olds and 144 8- and
9-year-olds representative of the general population.
Children ate diets free of the elements in mix A
and a second, more concentrated mixture of additives ("mix B,"
comprising sodium benzoate plus the dyes Sunset Yellow, carmoisine,
Quinolone Yellow, and Allura Red AC) for six weeks. During that time,
they drank a daily serving of plain juice (placebo) or juice containing
one of the two mixes; the test drink changed weekly. To measure
hyperactivity, the team calculated a global hyperactivity aggregate
(GHA) based upon questionnaires completed by parents, teachers, and
trained observers. Older children also completed a computer-based
assessment of attention. Small but significant increases in GHA
occurred with mix A in both age groups, with 3-year-olds showing a
greater effect. Mix B was associated with a small significant effect in
8- and 9-year-olds, but not in 3-year-olds, who had a wide range of
"The outstanding feature of the results was the
similar pattern of an adverse effect across both ages for both
mixes—although this did not reach statistical significance in every
case," says Stevenson. An unpublished study based on genetic samples
from the children examines these individual differences in greater
detail. "Our [forthcoming] data indicate that genetics rather than
anything else accounts for these individual differences in response
within an age group," Stevenson says.
Although the Southampton researchers conclude
that their results strongly support a relationship between food
additives and behavior, they do not claim that food additives cause
clinically defined ADHD. "It is very important to clarify that the food
additives and preservative studied only increased activity level
modestly," says Andrew Adesman, chief of developmental and behavioral
pediatrics at Schneider Children's Hospital in New Hyde Park, New York.
"I think the reasonable lessons from this study are that there may be
modest effects on activity level from additives or preservatives and
that better, more precise studies are needed to determine whether it is
the additives alone, the preservatives alone, or the combination that
is responsible for these modest adverse effects." The authors describe
these research needs with the additional requirement of considering the
time elapsed between additive consumption and subsequent behavior.
Nevertheless, after reviewing the Southampton
study, the British Committee on Toxicity concluded that the results
could be clinically relevant for individual children, particularly
those who already show a tendency toward hyperactivity. On the basis of
this study the British Food Standards Agency, which funded the
research, has advised parents to consider eliminating the colorings
used in the study from the diets of children who exhibit hyperactive
"It will be interesting to see how the [U.S.]
Food and Drug Administration reacts to this study," says Adesman.
"Hopefully, they will either encourage or mandate additional studies
looking at food effects of additives on children and also adults."
The FDA is aware of the Southampton study but has
not received the study data, according to administration spokesman Mike
Herndon. "We will examine this recent report to see if the results
suggest whether any action to modify our current regulations is
appropriate," he says. "However, we have no reason at this time to
change our conclusions that the ingredients that were tested in this
study that currently are permitted for food use in the United States
are safe for the general population."
Julia R. Barrett
Food Additives and Hyperactivity
Environ Health Perspect. doi:10.1289/ehp.11182 available via http://dx.doi.org [Online 27 May 2008]
Referencing: Hyperactive Ingredients?
In the December 2007 Forum article on the links between food
additives and hyperactivity, Barrett (2007) offered a somewhat
distorted perspective on the public health implications of these
additives. Barrett described a clinical trial testing the proposition
that consumption of a blend of artificial food flavors and sodium
benzoate induces changes in children's behavior (McCann et al. 2007).
The results of that study support such a claim.
Barrett (2007) fumbled the significance of the
trial (McCann et al. 2007) for environmental health. The Forum article
emphasized how food additives might contribute to the clinical
diagnosis of attention deficit/hyperactivity disorder rather than on
the more significant finding that food additives, particularly
synthetic colors at levels prevailing in the diet, induce adverse
behavioral responses. This is hardly a novel finding. In 1980, such
effects were documented in two different groups of subjects with two
different experimental designs (Swanson and Kinsbourne 1980; Weiss et
al. 1980). Many later publications have confirmed their results. I
briefly reviewed the data in
Environmental Health Perspectives (Weiss 2000).
According to Barrett (2007), a Food and Drug Administration (FDA)
official, Mike Herndon, maintains that the agency sees "… no reason at
this time to change our conclusions that the ingredients that were
tested in this study that currently are permitted for food use in the
United States are safe for the general population." This is a rather
baffling statement. In fact, our study (Weiss et al. 1980) was funded
by the FDA, and its results, along with a number of others from that
period, definitively demonstrated adverse behavioral effects of
synthetic food colors (Weiss 1982). During the intervening years, with
a plethora of confirmations, the FDA has remained blindly obstinate. It
continues to shield food additives from testing for neurotoxicity and
apparently believes that adverse behavioral responses are not an
expression of toxicity.
Herndon and the FDA should seriously consider what the late Philip Handler said about balancing risks and benefits:
A sensible guide would surely be to reduce exposure to hazard whenever
possible, to accept substantial hazard only for great benefit, minor
hazard for modest benefit, and no hazard at all when the benefit seems
relatively trivial. (Handler 1979)
The FDA has never clarified the health benefits of artificial food colors.
The author declares he has no competing financial interests.
Department of Environmental Medicine
University of Rochester School of Medicine and Dentistry
Rochester, New York
Barrett JR. 2007. Hyperactive ingredients? Environ Health Perspect 115:A578.
Handler P. 1979. Some comments on risk. In: The National Research
Council in 1979; Current Issues and Studies. Washington, DC:National
Academy of Sciences, 3–24.
McCann D, Barrett A, Cooper A, Crumpler D, Dalen
L, Grimshaw K, et al. 2007. 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 370:1560–1567.
Swanson JM, Kinsbourne M. 1980. Food dyes impair
performance of hyperactive children on a laboratory learning test.
Weiss B. 1982. Food additives and environmental
chemicals as sources of childhood behavior disorders. J Am Acad Child
Weiss B. 2000. Vulnerability of children and the
developing brain to neurotoxic hazards. Environ Health Perspect
Weiss B, Williams JH, Margen S, Abrams B, Caan B,
Citron LJ, et al. 1980. Behavioral responses to artificial food colors.
Weiss correctly points out that several investigators,
including himself, have reported links between food additives and
hyperactivity in children. He is also correct in stating that food
additives appear to exacerbate existing hyperactive behavior in
children, rather than contribute to the clinical diagnosis of attention
deficit/hyperactivity disorder (ADHD). The study by McCann et al.
[Lancet 370:1560–1567 (2007)] supports that conclusion, as described in
Barrett's December 2007 Forum article [Environ Health Perspect 115:A578
We believe it was
important to mention ADHD because hyperactivity and clinically defined
ADHD are often conflated in the science news press. The point of
referring to ADHD and therein clarifying the relationship between ADHD
and hyperactivity was to put the import of the findings by McCann et
al. (2007) into proper perspective. 118
Republished in verbatim from