Food Additives and Hyperactive Behavior

Scientific evidence is now conclusive that food additives can cause hyperactive behavior.
I say that clearly at the top, so there will be no confusion when I add:

  • Food additives do not cause ADHD
  • Food additives cause hyperactive behavior in only some children (my guess is that susceptible adults are more likely to suffer restlessness).
  • Elimination diets are an effective intervention for some children with hyperactivity problems.
  • A recent study in the American Journal of Psychiatry (September 2010 by Stevenson, et al) reported specific genes responsible of that hyperactive response.  Details below.

The information is interesting in its own right, of course, but I am taken with how slowly the information has flowed into the mainstream medical community.  I suppose that organized resistance to Benjamin Feingold’s 1975 report comes from the vested interests of food technology companies pushing academic  and practitioner skepticism; established doubt is not easily displaced.

That was certainly true for myself.  I held the position that food additive sensitivities was unproved.  It was only after a few parents were able to convince me that for their child, certainly, hyperactivity diminished when food additives were restricted.  I realized that, as with many other studies, important subgroups were statistically “unnoticeable” in amalgamated group studies.

In light of the new study, I have looked into the medical literature and found the evidence has been growing for years, unrecognized by most.

A report written for the Center for Science in the Public Interest by Jacobson and Schardt (1999) found on the web reviews 23 double-blind studies and reports that 17 of these studies found evidence that the behavior of some children are negatively affected following consumption of artificial colors or particular foods.

Elimination diets (to remove food coloring and sodium benzoate preservative) gained academic, if not clinical, respectability when a British group published a large placebo controlled study of 3 year olds in 2004 (Bateman et al).  Evidence of behavioral improvement was seen in the children who had elimination diets, whether or not they were clinically diagnosed with ADHD.  The same group (McCann et al) published a follow-up study of different children at ages 8-9 years who consumed a drink with a moderate level of additives or its placebo control.  Once again the conclusion was that the additives provoked hyperactive responses in a subset of the children.

The current study is from the same group (here, Stephens is the lead author).  This time, they studied the genetics of the responders vs. the non-responders in the two prior samples.  They studied single nucleotide proteins (SNPs) related to histamine and found “a link between histamine and ADHD symptoms in the HNMT gene moderating behavioral responses to food additives”.

The article concludes that these gene abnormalities (polymophisms) impair histamine clearance, and a food challenge causes histamine release—essentially, an allergic response, which affects the histamine receptors known to be in the brain.

To repeat, not all ADHD children had the abnormal gene pattern, and not all of those with the abnormality had diagnosable ADHD; but reliable observation scales demonstrated that those with the abnormality had hyperactive behaviors in response to the food additives.

Here is a list of the substances that provoked hyperactive reactions in the susceptible children:

  • Sodium benzoate
  • FD&C Yellow No. 6 (sunset yellow)
  • D&C Yellow No. 10 (quinoline yellow)
  • FD&C Yellow No. 5 (tartrazine)
  • FD&C Red No.40 (allura red)

Finally, I add an annoyed editorial comment.  I just read what is otherwise a good, thorough review of treatments for children with ADHD, subtitled “Current Evidence and Practice” in the Journal of Child & Adolescent Psychopharmacology, October 2008 (by Ghuman et al).  It’s a comprehensive review and has no mention of EEG neurofeedback.  Many other less helpful treatments are reviewed and, largely, dismissed (interestingly, only elimination diets for artificial colorings and preservatives are held as effective alternative interventions).  By now, the literature on neurofeedback for ADHD is solid enough that all reports should include it.

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