November 3, 2009 (Honolulu, Hawaii) — Overall nutritional status in children with attention deficit hyperactivity disorder (ADHD) shows that this patient population is at risk for low trace mineral status, including deficiencies in zinc and copper — minerals that may play a crucial role in the production of dopamine, norepinephrine, and melatonin, which regulates sleep.
Presented here at the American Academy of Child & Adolescent Psychiatry 56th Annual Meeting, a study conducted by investigators at the University of British Columbia and the Children’s and Women’s Health Centre in Vancouver, Canada, showed among 44 children aged 6 to 12 years with ADHD, rates of zinc and copper deficiency were 45% and 35%, respectively.
“There are a lot of studies in ADHD children looking at sugar intake, etcetera, but no one has ever actually looked at the dietary intake and subsequent nutrients of children with ADHD, ” principal investigator Margaret Weiss, MD, PhD, told Medscape Psychiatry.
With first author Joy Kiddie, RD, the study included 44 drug-naive and drug-treated ADHD children aged 6 to 12 years. Of these children, 17 were medication-naive, 18 were taking stimulant medications, and 9 were taking atomoxetine.
The children’s dietary intake was assessed using a 3-day food record and 24-hour recall. The food record assessed macronutrient/micronutrient intake relative to the recommended dietary allowances and food group recommendations.
The 24-hour recall was used to assess the percentage of low–nutrient density foods, or so-called “junk food” intake.
The study revealed that serum zinc below laboratory norms was present in 77% of children aged 6 to 9 years and 67% of children aged 10 to 12 years, and 25% of the children were below the cutoffs for zinc deficiency. Serum copper below laboratory norms was present in 23% of children.
No Difference in Junk Food Consumption
The investigators found that the study sample consumed comparable levels of protein, carbohydrate, and fat compared with recommendations and population norms, and ADHD children were no different than population norms in intake of low–nutrient density foods. However, 40% of the children consumed less than the recommended levels of meat and meat alternatives and had low levels of related micronutrients that are essential cofactors for the body’s manufacture of dopamine, norepinephrine, and melatonin.
Measurement of blood levels of micronutrients replicated previous findings of zinc deficiency and demonstrated copper deficiency for the first time. In addition, a majority of children had serum ferritin levels lower than 50 μg/mL, a level considered necessary for entry into the central nervous system.
“There is a commonly held belief that children with ADHD eat more junk food than other children, but the study did not confirm this view,” said Dr. Weiss. “However, our data suggest children with ADHD are nutritionally different from the rest of the population in that they eat less meat, fish, and poultry and have low levels of related micronutrients that are essential cofactors for the body’s manufacture of dopamine norephinephrine, and melatonin.”
Need to Focus on Nutrition
In a separate study of zinc supplementation also presented here at the American Academy of Child & Adolescent Psychiatry 56th Annual Meeting, Eugene Arnold, MD, and colleagues from The Ohio State University, Columbus, found that supplementation with 15 or 30 mg of elemental zinc made no difference to symptoms compared with placebo in a group of children diagnosed with ADHD after 13 weeks of treatment.
This study, said Dr. Weiss, raises many questions because previous research has suggested that zinc supplementation does make a difference. “It may not just be a question of what children eat but also whether they can absorb or metabolize zinc, or whether they are excreting it. In other words, is there some kind of phenomenon of zinc wasting?” she said.
Dr. Weiss said that, based on this study, it is too early to make any clinical recommendations beyond ensuring that children with ADHD have an adequate diet that includes appropriate levels of fish, meat, and poultry. However, she acknowledged, this can be a challenge in children on stimulant medications because of the drugs’ appetite-suppressing effect.
She added that it is important that clinicians with expertise in the assessment of nutritional status provide parents with information about good nutrition. “Traditionally, the emphasis on ADHD has been on treating the core symptoms of the disorder, but it is also important to assess and manage basic issues of health such as sleep, nutrition, and growth. Good health makes a difference,” said Dr. Weiss.
Dr. Weiss has disclosed that she is on the advisory board of and/or has received research or grant support from Eli Lilly and Company, Janssen, Purdue University, Shire Pharmaceuticals Inc, and Takeda Pharmaceuticals North America, Inc.
American Academy of Child & Adolescent Psychiatry 56th Annual Meeting: Abstract 17.3. Presented October 31, 2009.