ADHD, Food Dyes, and Additives: What's the Link?

Reviewed by Patricia Quinn, MD

You might have read that artificial food colorings can worsen ADHD symptoms such as inattentiveness and hyperactivity. And if you have a child with ADHD, you may have considered cutting out dyes and other additives from their diet.

Before you make any dietary changes, here are a few things you should know about the link between food colorings and ADHD.

The possible connection between ADHD symptoms and food dyes started with San Francisco pediatrician and allergist Benjamin Feingold. In the early 1970s, Feingold noted that hyperactive kids became calmer when they ate a diet free from artificial colors, flavors, and preservatives.

Since then, several studies have tried to confirm the link. What they've found is that, although dyes don't cause ADHD, a small percentage of kids with ADHD do seem to be sensitive to the effects of food dyes and other additives.

After looking at 34 different studies, "We concluded that there is a small association of food dyes with ADHD," says Joel Nigg, PhD, a professor of psychiatry and behavioral neuroscience at Oregon Health & Science University and author of What Causes ADHD?

In Nigg's review, about 8% of children showed symptoms related to food dyes, and about 30% responded well to a dye-free diet.

Yet Nigg says there are still some open questions. The studies that have been done so far have mostly included small numbers of children: in some cases, just 10 or 20 kids. Plus, many of the children ate foods that had both dyes and other additives, making it hard to pinpoint the exact cause of their behaviors.

Researchers also aren’t sure exactly how artificial food colorings might impact ADHD symptoms. It could be that these substances affect children's brains. Or, it's possible that some kids are hypersensitive: They have a kind of allergic reaction when exposed to dyes and additives, Nigg says. Many of the kids who are sensitive to dyes are also sensitive to other foods, like milk, wheat, and eggs.

In 2007 study linked six different food dyes to increased hyperactivity in children. After the study's release, the European Union started requiring warning labels on foods containing the dyes tested in the study:

quinoline yellow (yellow #10)ponceau 4R (not available in the U.S.)allura red (red #40)azorubine (not approved for food in the U.S.)tartrazine (yellow #5)sunset yellow  (yellow #6)

The U.S. didn't set similar requirements. In 2011, an FDA Food Advisory Committee concluded there isn't enough evidence to prove food dyes cause hyperactivity in children.

Although the link between food dyes and ADHD symptoms is still not clear, some parents say they have seen an improvement after eliminating these and other additives from their children's diet.

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