Smarter Living: Family Health

Photo: Andy Langager

Your child can't sit still in class. He loses interest quickly when reading or doing a math problem. Could the chemical dyes in food be to blame?

Evidence is accumulating that synthetic food dyes do indeed contribute to hyperactivity, a symptom of attention deficit/hyperactivity disorder (ADHD). The strongest evidence yet of the link between synthetic colorants and ADHD symptoms comes from two UK studies published in 2007.

The studies, funded by the British Food Standards Agency and conducted by researchers at Southampton University, found that ingesting a mixture of dyes plus the preservative sodium benzoate increased hyperactive behavior in three-year-olds and eight- to nine-year-olds. The results are considered important because they were conducted on a sample of children from the general population, not children who had already been diagnosed with ADHD or whose parents suspected dyes were to blame. To ensure objective results, neither the researchers, parents or children knew whether they were receiving food dyes or a placebo.

As with any study results, these have their limits: The researchers acknowledge that it is impossible to know which of the dyes was responsible for the effect on behavior. Sodium benzoate, included in the mix as a preservative, could also have been to blame. Two of the dyes (Red 40 and Yellow 5) are used in the United States.

Nonetheless, the findings were compelling enough that the U.K.'s food regulatory agency has asked manufacturers to pull artificial dyes from foods in stores and restaurants. The U.S. Food and Drug Administration, however, denies any link between the nine FDA-approved synthetic food dyes and ADHD symptoms.

ADHD Defined

ADHD is characterized by inattention, impulsivity and hyperactivity to the degree that the child has an impaired ability to learn and function at home and at school. About three to seven percent of school-aged children suffer from ADHD, according to the Centers for Disease Control and Prevention (CDC). The disorder tends to run in families, so genetics plays an important role. Prenatal exposure to lead and environmental tobacco smoke are also potential culprits, as is alcohol use during pregnancy.

While food dyes are unlikely to be the cause of ADHD in most children, the Southampton studies plus many others indicate that food dyes can make the symptoms of ADHD worse in some children. What is more, the chemicals have this effect whether the child is identified as having ADHD or not.

The Growing Use of Food Dyes

Food dyes are increasingly common in foods marketed to kids. The amount of dyes produced per person in the U.S. rose five-fold from 12 milligrams (mg) per day in 1955 to 59 mg per day in 2007, according to the Center for Science in the Public Interest, which in 2008 called on the FDA to ban synthetic food dyes. Ironically these colors are added to make food look like the flavorful fruits that kids love, such as ripe strawberries and sweet blueberries.

Many parents are choosing to steer clear of food dyes and giving their children whole fruits and vegetables instead. Food products are required to list colorants on the label, but not all dyed foods come in labeled packages. "If a parent is aware that the child is sensitive [he or she] can avoid it on packaged foods," Michael Jacobson, executive director of the CSPI, says "but at parties or restaurants it is impossible to know whether food dyes are used."

What You Can Do

• Check labels: avoid products with ingredients lists that include sodium benzoate and artificial colors, colorants, dyes or any of the colorants listed in the sidebar
• Buy whole, organic foods, which cannot contain artificial dyes or sodium benzoate and feed your children lots of whole fruits and vegetables.
• For cakes and other items, use natural food dyes made from beets (red), paprika (yellow), red cabbage (blue).

last revised 1/3/2012