What’s the link between artificial food dyes and ADHD?
There has been lots of talk lately about artificial colorings used in processed foods and whether they may cause hyperactivity in kids. Last week, in response to a petition from the Center for Science in the Public Interest, an FDA committee held hearings to decide whether to recommend changing the rules for these ingredients.
Even though the FDA committee concluded that there was not enough evidence to warrant banning these ingredients—or even including a warning on foods that contain them, many parents are very concerned about this issue. At the end of the article, I have some guidelines for those who want to take matters into their own hands.
But first, let’s take a closer look at the evidence on the connection between artificial dyes and hyperactivity.
Does Food Coloring Make Kids Hyper?
The idea that food colorings might be linked to hyperactivity in kids dates back to the 1970s, when a pediatrician named Ben Feingold proposed a diet that eliminated all artificial colorings and preservatives as a treatment for hyperactivity. He claimed that this protocol was highly effective in reducing symptoms. Other experts have questioned his results, claiming that when kids didn’t do well on the diet, he simply excluded those cases from his data.
What’s the Evidence on Artificial Dyes and Hyperactivity?
Nonetheless, Dr. Feingold’s hypothesis spurred others to research the question. It turns out that this is a tricky subject to study. Measuring the level of hyperactivity in a child is essentially a subjective judgment, and it turns out that the results depend a lot on who is doing the rating. For example, it seems that parents are more likely to rate their children’s behavior as hyperactive than teachers or clinicians are. Not surprisingly, their expectations also color their judgments. When parents think their kids have been given food additives, they tend to perceive an increase in hyperactive behavior—whether or not the kids actually did ingest them.
Even if you only look at double-blind, placebo-controlled studies—the so called gold standard of research design—the results are inconsistent, to say the least. Of 15 trials that met those criteria, five found that food colorings seemed to increase hyperactive behavior. Eight found no relationship. And two studies even found that food coloring seemed to decrease hyperactive behavior!
Why Studies on the Link Between Food Coloring and Hyperactivity Are Problematic
In a recent presentation on the topic, pediatric specialist Dr. Keith Ayoob pointed out another strange anomaly. In a 2007 study, the data for one group of kids showed an association between food coloring and hyperactivity only at the higher of two test doses—which makes sense. But for another group of kids in that same study, the association was only seen at the lower of the two doses. That makes no sense.
Finally, even though the various food colorings have very different chemical compositions, they haven’t been tested one by one. Most of these studies have used a cocktail containing several different food dyes plus sodium benzoate, which is a common preservative. So even when a link has been detected, there’s no way to know which of the several chemicals might be responsible.
Will Food Coloring Make Your Kids “See Red?”
Based on the existing evidence, I don’t expect the FDA to make any changes regarding food coloring. But you don’t need the laws to change in order to improve your child’s diet.
That doesn’t keep parents from drawing their own conclusions. Recently, I was listening to an interview with a mom who claimed that she could tell which artificial colors her child had eaten based on his behavior. Red dye made him aggressive and hostile, she said. Blue, on the other hand, made him weepy and sad. Notice that the associations she observed line up exactly with common idioms. When people are angry, we often say they are “seeing red.” And when we’re depressed, we say we are “feeling blue.” It’s a pretty striking coincidence.
Food dyes may be related to behavior changes in some kids. For now, however, the FDA doesn’t feel that the existing evidence is solid enough to warrant banning these additives or even requiring warnings. But you don’t need the laws to change in order to make changes in your child’s diet.
4 Things Parents Need to Know about Food Dyes and Hyperactivity
Food dyes aren’t a problem for most kids. Some kids, however, appear to be especially sensitive to the additives. For these children, avoiding foods with artificial colorings may be helpful. (If you’re trying to avoid synthetic dyes, keep in mind that they are often used in children’s medications as well)
Eliminating food dyes may not completely solve the problem. ADHD usually has many contributing factors. If your child is sensitive to food dyes, avoiding them may help but will probably be only one part of the solution.
A healthy diet is low in food dyes, anyway. The primary sources of food dyes are brightly colored candy, breakfast cereals, sweetened beverages, and other processed foods. Even if the FDA did require manufacturers to take the artificial colorings out of these foods, you still wouldn’t want your kids eating that stuff in large quantities. The easiest way to minimize your child’s exposure to synthetic dyes is to limit his consumption of these foods. That will also improve the nutritional quality of your child’s diet—which is also likely to have a positive impact on learning, mood, and behavior.
Don’t sweat the small stuff. Eliminating every trace of artificial coloring from your child’s diet would be a very tough job. Fortunately, this is not like a peanut allergy where the smallest particle of peanut could bring on a life-threatening reaction. In the most recent study, for example, the amount of food dye that was linked to behavior change was the equivalent of an 8-year-old eating a half pound of candy in a single sitting. The same behavior changes were not seen at lower amounts.
From a purely practical perspective, the question of whether these dyes really are responsible for hyperactive behavior is kind of moot. Either way, a diet containing large amounts of synthetic dyes is probably not a good choice for kids or adults.
Below, you’ll find citations for some of the research that I reviewed. Feel free to post your comments here or on the Nutrition Diva Facebook page.
Bateman et al, The effects of a double blind, placebo controlled, artificial food colourings and benzoate preservative challenge on hyperactivity in a general population sample of preschool children. Arch Dis Child., 2004, 89: 506-11
Feingold, BF. Behavioral disturbances linked to the ingestion of food additives. Delaware Medical Journal 1977 Feb;49(2):89-94.
McCann D, Barrett A, Food additives and hyperactive behaviour in 3-year-old and 8/9-year-old children in the community: a randomised, double-blinded, placebo-controlled trial. Lancet. 2007 Nov 3;370(9598):1560-7.
Schab DW, Trinh NH. Do artificial food colors promote hyperactivity in children with hyperactive syndromes? A meta-analysis of double-blind placebo-controlled trials .J Dev Behav Pediatr. 2004 Dec;25(6):423-34.