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BLOG: June 2008

Do artificial food colors cause hyperactivity?

It all started back in the mid 1960s, when then little known San Francisco allergist, doctor Ben Feingold, through his practice, became aware of the link between food additives - particularly artificial food coloring agents - and so called hyperkinetic behavior, or hyperactivity, often associated with irritability, and difficulty to concentrate.

Food coloring agents also seemed to be directly implicated in causing allergic reactions - such as hives, skin lesions, respiratory and gastrointestinal symptoms, even skeletal disorders - in sensitive individuals.

In the following years, results of a number of trials carried out by Feingold, including some 1,200 cases, confirmed the link. However, many other studies up to this day have failed to come to a common conclusion. This created a limbo to this day, with the general public - including parents - inclined to think that food additives do affect children's behavior, while organized medicine generally denying it.

The later opinion is shared by the government's regulative agency (FDA), and - needless to say - by food manufacturers.

Not surprisingly, recent initiative by the Center for Science in the Public Interest, a non-profit consumer advocacy group, asking the FDA to require warning label on colored foods or - preferably - ban artificial colors altogether, haven't gotten worm reception by the agency. It keeps arguing that there is no reliable study confirming the alleged adverse effect of food coloring agents, and that color additives undergo safety reviews prior to approval.

Is it really so plain and simple?

Not at all. A number of researchers after Feingold did find clear correlation between ingesting artificial food colors - among other food additives - and adverse changes in behavior, including hyperactivity. The most recent study on 277 three-year-olds, the largest controlled study of this type to date (Bateman at al., 2004), has concluded that there is

significant adverse effect of food additives

(20mg of artificial food colorings and 45mg sodium benzoate daily) on children's behavior in all four groups: those with ADHD (attention deficit/hyperactivity disorder), with allergies, with both and with neither condition.

That is, the adverse effect is significant according to parents' reports, but not according to the parallel clinical test assessments, based on inattention or impulsivity while playing computer games. Such division in the opinion between parents and medical professional is rather typical. Noting that neither parents nor those conducting clinical testing knew when the children are in active (receiving additives) or placebo periods, the choice of tool for the clinical assessment doesn't seem to be very wise, or efficient, in this particular case.

The study prompted move for a review and new regulations for food additives in Britain, but Britain's FDA equivalent, Food Standard Agency, wasn't receptive. Similarly to the FDA, they want more studies that would reproduce similar results, pointing out that food additives are subject to "strict safety checks before they can be used in foods".

One has to wonder what is it that makes food coloring agents so precious in the eyes of government agencies entrusted with protecting public health and wellbeing? There is absolutely no benefit for the consumer from their use; their only purpose is to make foods visually more attractive, thus to boost food manufacturer's profit. Why is it that the agencies so stubbornly insist to be given ever more evidence of their adverse effects?

Well, it is not just about artificial food colors. The Bateman study plunged right into the "no-no" territory by implicating other types of food additives (specifically preservatives) as causing adverse health effects as well. The thing is, any significant restriction in use of all food additives would be too big - or should we say too expensive - a pill for food industry to swallow. It is not necessarily about special interests stepping in; but it is about the interest of protecting economic prosperity and strength

spilling over to where it is not supposed to:
in the public health protection domain.

There are the reasons why some studies have not confirmed link between artificial food colorings - and other food additives - and adverse changes in behavior, or allergic reactions. It is not a secret. Most of those were the U.S. studies financed by the Nutrition Foundation, an organization financially linked to major food manufacturers.

The principal study cited as negating Feingold's results (C. K. Conners) used chocolate cookies as placebo (majority of hyperactive children react on chocolate and other ingredients present in these cookies, like milk, sugar, wheat, food additives), had unrealistically low doses of mixed food dyes (13mg twice daily, despite FDA's estimate that the average daily intake for 5-12 year old was 76.5mg a day, with the maximum consumption exceeding 300mg/day), too long dose intervals, inadequate rating scales7 and interpreted positive data as negative (i.e. "no effect") by setting unrealistic standards - or simply ignoring it.

Similarly biased designs were rather common in other studies that had direct or indirect financial link to food industry.

On the other hand, majority of studies outside the U.S. have found

overwhelming evidence in support of Feingold' hypothesis, that food additives, among other chemical agents (natural salicylates, artificial flavors, phenolic compounds in general),

do cause hyperkinetic behavior,

as well as other adverse health effects, particularly in children.

That said, there are some objective difficulties in evaluating these effects, that can also compromise reliability of the results. They include: (1) often hard to control compliance with children participants, (2) great chemical complexity of our bodies, (3) often unpredictable chemical interactions, and (4) individual variations to a specific stimulus.

Experiments on animals, while not directly correlated to humans, also clearly show that food additives are capable of adversely affecting their behavior, broader neurologic function and pathology. Test tube studies have shown food dyes to be damaging to the nerve tissue4.

As for claimed "safety review" of food additives by the FDA prior to their approval, it simply

does not address their possible behavioral,
or longer-term health effect.

Their screening of toxicity tests by manufacturers - and those very tests themselves - are limited to the possible harm to major body organs - primarily liver - or tissues, and possible carcinogenic properties. There is no testing - nor screening - for behavioral, long-term, or other forms of toxicity whatsoever. It would be just "too expensive".