ADHD Worsened by Food Coloring and Food Preservatives

On March 30th and 31st of this year, the Food and Drug Administration (FDA), Food Advisory Committee, will meet to discuss whether "Available relevant data demonstrate a link between children's consumption of synthetic color additives in food and adverse effects on behavior."

This FDA meeting is long overdue. Europe began to band the use of certain food dyes and preservatives after a well respected study was published in the Lancet in 2007.  The Lancet study was a case/control trial that ended up showing a convincing link between hyperactivity and inattention in children consuming food dyes and preservatives. The authors of the Lancet study concluded, that "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 in the general population."

According to the FDA, Americans consume five times as much food dye as they did 30 years ago. During this same time we have seen an exponential increase in the number of children and adults diagnosed with ADHD. All of us should be infuriated by the fact that, in Europe, McDonalds uses real strawberries to color their strawberry sundaes while in the U.S. the sundaes are colored with red dye #40.

The British government now requires food label warnings on any foods that contain food dyes. Not wanting a warning label on their food products, every major American food manufacturer selling food in Europe has removed food dyes from their European products. These companies produce foods that are to be sold in Europe, with natural colorings. The same foods, that are to be sold in the U.S., contain synthetic dyes.

The Lancet study that I discuss above did not test the effect of food dyes on kids with ADHD. The kids tested were sampled from the general population. The researchers who conducted this study took genetic laboratory tests from these kids prior to starting the study. They suspected, at the time of their study that the kids that had an adverse reaction to the food dye and preservatives would have a certain genetic make up that would predispose them to these reactions.

The researchers came up with their gene theory because they were trying to understand and give an explanation for why certain, well performed, food additive research studies showed consistent behavioral changes in children who consumed food dyes while other studies could not replicate these findings.

A follow-up paper with the results of their gene study was published a few months ago. They found that the adverse effect of food additives on ADHD symptoms was moderated by histamine degradation genes and by a DAT1 gene. They concluded that the inconsistencies in previous reports regarding food additives and hyperactive and inattention symptoms might be explained by gene variations influencing the action of histamine.

These findings confirm what the researchers had predicted that the food dyes may be causing more hyperactivity in certain kids and adults with genes that react badly to these food dyes. We know that the DAT1 gene is one of the genes that have been linked with ADHD symptoms so it would seem obvious, given the findings of this recent study, that we should (at the very least) avoid giving food dyes to kids diagnosed with ADHD.

In the U.S. this will not be easy. Food dyes are present in junk food but they are also present in most food that is packaged and brightly colored. Sodium Benzoate has also been linked with ADHD like symptoms and it is a food preservative found in many packaged foods. The best we can do for now is to diligently read food labels and avoid the dyes that are the most likely to worsen ADHD symptoms. These would include: certified color Red #40, Blue #2, Yellow #5 (Tartrazine), Yellow #6 (Sunset Yellow), as well as sodium benzoate.

I will be following the Food Advisory Committee hearings carefully. It would seem that the evidence that we have now is convincing enough to warrant the FDA banning or placing warning labels on foods that contain food dyes. I will keep you posted.

American Journal of Psychiatry. 2010 September
The role of histamine degradation gene polymorphisms in moderating the effects of food additives on children's ADHD symptoms.
Stevenson J, Sonuga-Barke E, McCann D, Grimshaw K, Parker KM, Rose-Zerilli MJ, Holloway JW, Warner JO.

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