Commentary: FDA: No link between food colorings and hyperactivity in most children




Commentary

Parents, advocacy groups, and some scientists have long worried about a possible link between artificial food colorings and hyperactivity in children. In March 2011, an FDA panel concluded that there isn’t enough evidence to prove that artificial food colorings contribute to hyperactivity, distractibility, and other behavior problems in most children. They did not find evidence that the substances are inherently toxic to the nervous system. Rather, the panel wrote that certain children with attention deficit hyperactivity disorder (ADHD) may be uniquely vulnerable, not just to food colorings, but to any number of food additives. On that theme, only a small minority of children are vulnerable to the effects of artificial additives and it’s difficult — and in practical terms, almost impossible — to determine who they are.

The FDA convened the Food Advisory Committee to review the scientific evidence on artificial dyes and hyperactivity after receiving a 2008 petition submitted by the Center for Science in the Public Interest (CSPI). The CSPI asked the FDA to ban food dyes used in commercially prepared food.

For more than 30 years, researchers have been examining whether synthetic dyes and other chemicals might contribute to behavioral changes in children. Teasing out whether food coloring causes ADHD or if the two are merely associated is a tall order. By no means do the experts have it sorted out yet. The FDA committee’s vote was in line with the consensus view among scientists, that diet alone is probably not the driving force behind ADHD symptoms such as inattention, hyperactivity, or impulsive behavior.

Yet the FDA’s ruling — and several studies — suggested that food additives could contribute to symptoms in some children. In 2007, for example, a well-designed study in Britain found that preschoolers and elementary school students became slightly more hyperactive when they consumed drinks containing artificial colors. Using a complex calculation of “effect size,” the investigators estimated that the additives might explain about 10% of the behavioral difference between a child with ADHD and one without the disorder.

This was similar to the effect size reported in an earlier review by researchers at Columbia University and Harvard University, who estimated that removing artificial food colorings from the diets of children with ADHD would be about one-third to one-half as effective as treatment with methylphenidate (Ritalin).

Here is some advice for those who are worried about the impact of artificial colorings in food:

Avoid a radical approach. For most children with ADHD, there is no evidence that radical diets that eliminate nearly all processed foods and many fruits and vegetables — such as the Feingold diet — do any good. And there is no easy way to identify the few children who might benefit from diets that ban particular foods.

Try eliminating some foods. If you are concerned about behavior changes in your child, or yourself, experiment a bit. Try removing the major dietary sources of artificial colors and additives and see if symptoms improve. The major sources are candy, junk food, brightly colored cereals, fruit drinks, and soda.

Follow a sensible diet. The best advice for anyone with ADHD is to follow a sensible diet. Emphasize fruits and vegetables, whole grains, healthful unsaturated fats, and good proteins. Go easy on unhealthy saturated fats and trans fats, typically found in fast food or prepared meals.

Start moving. Physical activity is great for the brain as well as the body. Children (and adults) benefit when they have time to participate in sports, take dance classes, or just play — outdoors or inside.

You’ll notice that these recommendations are healthy recommendations for anyone. Minimizing candy and sugared drinks, eating a truly balanced diet, adding physical activity to the menu — these habits will have any number of health benefits (both for the body and the brain). I don’t make these suggestions lightly. I know how difficult it is to get your child (especially a child with behavioral difficulties) to eat his or her vegetables. But I also believe it is wise not to let concern over food additives distract parents from established guidelines for healthy eating.

— Michael Craig Miller, M.D.
Editor in Chief, Harvard Mental Health Letter

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