New Studies Link Diet and Behavior

by Jane Hersey

Prompted by studies showing a strong link between artificial food dyes and hyperactivity, the European Union now requires labels on most dyed foods to warn that the additives “may have an adverse effect on activity and attention in children.” The US government has been much slower to react to this research, but two new studies may help to shake things up here.

An Australian study, published online in the international Journal of Attention Disorders on July 29, examined the dietary patterns of 1800 adolescents, of whom 115 were diagnosed with ADHD by age 14.

This study, from Perth’s Telethon Institute for Child Health Research, found that teens who ate a highly processed, Western-style diet were more than twice as likely to be diagnosed with attention deficit/hyperactivity disorder (ADHD) as those who ate more healthful diet.

The researchers suggested several possible reasons for the link between a Western-style diet and ADHD, including the artificial food dyes, flavors, and other additives found in processed and fast foods. They also cited the diet’s lack of essential micronutrients, omega-3 fatty acids, and folate.

Another new study, published in the American Journal of Psychiatry, explores a possible mechanism behind the link between artificial food dyes and ADHD symptoms. It also sheds light on why these additives have a very powerful effect on some children and a milder effect on other s.

The answer may lie in the children’s genetic makeup, according to the authors. They found that children with certain slight variations in the HNMT gene, which helps break down histamine in the body, have stronger behavioral reactions to food dyes than those without the variations.

While histamine release is known to be involved in the sneezing, coughing, and runny noses associated with the common cold, the authors noted that this compound also affects transmission of nerve signals in the brain. They explained that children with these gene variations have trouble degrading the histamine released by their bodies in response to the food additives and that the neurological effects caused by the excess histamine results in increased hyperactivity.

The researchers pointed out that, in addition to environmental toxins like artificial food additives, many foods and infections also increase histamine release. “This would explain the frequent claim that food allergy/intolerance is a cause of ADHD symptoms and the effects of infections in aggravating aberrant behavior,” they wrote.

The authors also called for further research on the interaction of genes that affect neurological systems and environmental factors like diet, in order to better understand genetic influences on ADHD symptoms.

This study was based on a highly acclaimed 2007 trial published in the Lancet, which concluded that synthetic food dyes exacerbate hyperactive behavior in children from the general population, not just those diagnosed with ADHD.

The American Journal of Psychiatry study also cited a 2004 meta-analysis of 23 controlled trials (including 15 with exclusively hyperactive children), which showed that children’s behavior is affected by artificial food dyes and called for an “ambitious vigil against avoidable harmful exposures.”

This research led representatives from the Feingold Association and the Center for Science in the Public Interest to meet with Food and Drug Administration officials on March 1 in Washington, DC, where they called for removal of synthetic dyes from the food supply or, at a minimum, warning labels.

We hope that these efforts will result in the eventual disappearance of

no nutritional value and are actually harmful, they have no place in the foods we are feeding our children.

Since 1976, the nonprofit Feingold Association (www.feingold.org ) has helped parents of special-needs children use the Feingold Diet, which eliminates synthetic food dyes, artificial flavorings, and certain preservatives. This diet was developed by pediatrician/allergist Dr. Ben Feingold. The charity’s advisory board and board of directors include medical professionals from Johns Hopkins University, the University of Rochester, Stony Brook University, Baltimore’s Sinai Hospital, and other institutions. The charity conducts in-depth research with food companies and provides members with information about which foods are free of harmful additives. Its “Foodlists” contain thousands of acceptable brand-name products, and its Pure Facts Newsletter provides frequent updates. Membership benefits also include a handbook on the Feingold diet, a Foodlist & Shopping Guide, a Fast Food & Restaurant Guide, a mail-order guide, phone and e-mail help lines, an online chat room, and a message board. Individual dietary needs vary, and no one diet will meet everyone’s daily

requirements. Before starting any new diet, check with your doctor or

Jane Hersey, who volunteered to work for the Feingold Association after the low-additive Feingold diet helped her eldest daughter, is now the charity’s national director. A former teacher and Head Start consultant, she is also author of Why Can’t My Child Behave? She has testified before the National Institutes of Health, the US Department of Agriculture, and Congress about ADHD and diet. She frequently lectures at education associations, hospitals, medical groups, universities, and schools, and she spearheaded one of the first low-additive school food programs in the country in the 1980s.

References

European Parliament. Modernising the rules on food additives and labelling of azo dyes [online press release]. July 8, 2008.

Howard AL, Robinson M, Smith GJ, et al. ADHD is associated with a “Western” dietary pattern in adolescents. J Atten Disord. 2010; doi:10.1177/1087054710365990.

McCann D, Barrett A, Cooper A, et al. 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. Nov 2007;370(9598):1560–1567.

Schab DW, Trinh NT. Do artificial food colors promote hyperactivity in children with hyperactive syndromes? A meta-analysis of double-blind placebo-controlled trials. J Dev Behav Pediatr. Dec 2004;25(6):423–434.

Stevenson J, Sonuga-Barke E, McCann D, et al. The role of histamine degradation gene polymorphisms in moderating the effects of food additives on children’s ADHD symptoms. Am J Psychiatry. June 15, 2010; doi:10.1176/appi.ajp.2010.09101529.