WASHINGTON — In a new review of two dozen scientific studies, the nonprofit Center for Science in the Public Interest (CSPI) contends that food dyes and certain foods can adversely affect children’s behavior. CSPI, in a 32-page report titled "Diet, ADHD, and Behavior," charges that federal agencies, professional organizations, and the food industry ignore the growing evidence that diet affects behavior.

The report cites 17 controlled studies that found that diet adversely affects some children’s behavior, sometimes dramatically. Most of the studies focused on artificial colors, while some also examined the effects of milk, corn, and other common foods. The percentage of children who were affected by diet and the magnitude of the effect varied widely among the studies. Six other studies did not detect any behavioral effect of diet.

"It makes a lot more sense to try modifying a child’s diet before treating him or her with a stimulant drug," said Dr. Marvin Boris, a pediatrician in Woodbury, New York, whose 1994 study found that diet affected the behavior of two-thirds of his subjects. "Health organizations and professionals should recognize that avoiding certain foods and additives can greatly benefit some troubled children."

Several experts on diet and behavior joined Boris today calling on Donna Shalala, Secretary of the U.S. Department of Health and Human Services (HHS), to encourage parents and professionals to modify children’s diets before resorting to drug treatment. They asked HHS to undertake new research into the link between diet and behavior and to "consider banning synthetic dyes in foods and other products (such as cupcakes, candies, sugary breakfast cereals, vitamin pills, drugs, and toothpaste) widely consumed by children." Those experts include Ted Kniker, University of Texas Health Science Center at San Antonio, and Joseph Bellanti, Georgetown University Medical Center.

ADHD’s main symptoms are reduced attentiveness and concentration, excessive levels of activity, distractability, and impulsiveness. An estimated three to five percent of school-age children have ADHD, though some surveys put the percentage as high as 17 percent. Stimulant drugs, such as Ritalin and amphetamines, are often highly effective in reducing the symptoms of ADHD, and millions of children have been treated with them. One recent study found that 18 to 20 percent of fifth-grade white boys in two cities had been diagnosed with ADHD and were being treated with stimulant drugs.

Ritalin and other drugs sometimes cause side effects, including reduced appetite, stomachaches, and insomnia. A 1995 study conducted by the federal government’s National Toxicology Program (NTP) found that Ritalin caused liver tumors in mice.

"The NTP study sends a strong warning that Ritalin may cause cancer—in the liver or other organs—in humans. Millions of young children take Ritalin for long periods of time, and children may be especially vulnerable. It would be prudent for HHS to discourage doctors from prescribing Ritalin, especially in the absence of an explicit warning about the cancer risk," says Samuel Epstein, professor of occupational and environmental health at the School of Public Health, University of Illinois Medical Center in Chicago.

Epstein and several other cancer specialists, including Emmanuel Farber, University of South Carolina School of Medicine, Marvin Legator, University of Texas Medical Branch at San Antonio, and Richard Clapp, Boston University, urged HHS to sponsor new animal and human studies on Ritalin and other stimulant drugs.

"The Department of Health and Human Services should withdraw its printed and internet documents that largely dismiss the effect of food ingredients on behavior. For starters, the FDA should halt distribution of a pamphlet on food additives that it co-published with an industry group, the International Food Information Council," said Michael F. Jacobson, executive director of CSPI and lead author of the report. "It’s high time that the government — as well as doctors — provided the public with accurate information that might help many children."

This report reviews 23 controlled studies of the effects of food dyes and other dietary constituents on the behaviour of children with ADHD or other behavioural problems.

17 of the 23 studies found evidence that some children's behaviour significantly worsens after they consume artificial colours or certain foods such as wheat or milk. Limited research with such tools as electroencephalography (EEG) indicates that certain foods trigger physiological changes in sensitive individuals.

Notwithstanding the evidence from numerous studies, many health organisations and medical experts deny that diet can provoke adverse behaviours and that modified diets may benefit patients. The National Institutes of Mental Health (NIMH) largely dismisses diet as a treatment approach. The US Food and Drug Administration (FDA) has co-sponsored with an industry trade organisation a misleading pamphlet that denies the effect of diet on behaviour.

Ignoring or denying the effect of diet on behaviour is not helpful to children and their families. The federal government, the food industry, organisations concerned about children with behavioural problems, and psychiatrists, psychologists, and social workers should recognise that diet can help children who have behavioral problems. Parents should consider modifying their children's diets for several weeks to ascertain any benefit before resorting to medications. That is particularly the case because the stimulant drugs routinely used to treat ADHD may cause side effects, and the most commonly used drug, methylphenidate (Ritalin), increased the incidence of liver cancer in a study on mice. Of course, modifying a child's diet can be difficult in a society in which problems foods are ubiquitous, although perhaps no more difficult than adhering to a vegetarian diet.

Recommendations.

• that parents consider dietary changes as the first course of treatment.
• that the FDA should consider banning any dyes in food widely consumed by children and other foods that affect behavior.
• that schools, camps, paediatric hospitals and clinics should minimise the use of food additives that may contribute to behavioural disorders.
• that fast food chains and manufacturers of foods, drugs, and vitamin supplements popular with children should minimize the use of dyes and other unnecessary additives.
• that the National Institutes of Health (NIH) should conduct studies to investigate possible long-term effects (carcinogenic, behavioral, reproductive, teratogenic) of other stimulant drugs.
• that the National Institutes of Health should develop methods for identifying children most likely to be at risk for behavioral problems caused by diet and to "develop techniques to reduce the impact of foods on children's behavior".

In particular, CSPI recommends that the government consider banning synthetic dyes in products widely consumed by children, including cupcakes, candies, sugary breakfast cereals, vitamin pills, drugs, and toothpaste. The use of such dyes, the report notes, has increased four-fold in the past four decades.