Attention Deficit Hyperactivity Disorder: Nutritional Considerations

The role of diet in ADHD has been controversial ever since it was first proposed in the book Why Your Child Is Hyperactive, by pediatrician Ben Feingold, M.D. Dr. Feingold demonstrated that the removal of synthetic colorings, flavorings, and preservatives from the diet led to a significant improvement in many children. Subsequent studies suggested that the benefits of diet change may have been largely due to a placebo effect. However, continuing research has suggested that diet may indeed play a role in ADHD.

The following nutritional factors are under study for their effect on ADHD:

• Diets free of artificial flavorings, colors, and common allergens: At least eight studies have demonstrated significant behavioral improvement on low-allergen diets compared with regular diets. Typical low-allergen diets used in clinical studies have included only lamb, chicken, potatoes, rice, banana, apple, cabbage, cauliflower, Brussels sprouts, broccoli, cucumber, celery, carrots, parsnip, salt, pepper, calcium, and vitamins.
• Omega-3 fatty acids: Omega-3 fatty acids (found in fatty fish and various nuts and seeds, such as walnuts and flax seeds) have been reported to be lower in children with ADHD, compared with other children, suggesting that adding omega-3 fatty acids, either as foods or as supplements, may be beneficial. However, clinical trials of these fatty acids in children with ADHD have produced inconsistent results. Of six placebo-controlled studies, only three showed positive results.
• Zinc: Zinc influences several brain chemicals that may play roles in ADHD. Low zinc levels have been found in hyperactive children, compared with controls. Controlled clinical trials in the Middle East, an area of zinc deficiency, support the possibility that supplemental zinc (55 to 150 milligrams per day) may improve the response to stimulant medications or improve symptoms of hyperactivity and impulsive behavior when used alone. However, further controlled clinical trials are required.
• Sugar restriction: Controlled trials of sugar-restricted diets found no effect on behavioral symptoms, even in children thought to be sugar-sensitive.
• Aspartame restriction: Studies have not yet supported a role for aspartame (NutraSweet) in ADHD.
• Mineral supplements: Deficiency of several minerals (iron, copper, zinc, and calcium) may influence brain function, and several studies have demonstrated mineral deficiencies in children with ADHD. However, controlled studies have not established a clear benefit of supplementation in individuals with ADHD.