No one can say with certainty that certain foods aggravate or relieve the symptoms of attention deficit hyperactivity disorder (ADHD) in children. However, clinical and some research evidence does indicate that at least some children with ADHD or ADHD-like symptoms could benefit from avoiding (or eating) certain foods or ingredients.
Food Additives
Proponents of the theory that foods can cause or aggravate ADHD focus a lot of attention on food additives such as artificial colorings and preservatives such as benzoate. The Center for Science in the Public Interest reported that because of differences in studies, children and types of additives, it's hard to draw firm conclusions from the research. But food additives and preservatives do seem to aggravate ADHD symptoms, especially hyperactivity, in at least some children.
Salicylates
Salicylic acid is the active ingredient in aspirin. Salicylates are found naturally in some foods, including many fruits and some vegetables. The first stage of the Feingold Diet, an additive-free diet designed in the 1970s by allergist Dr. Benjamin Feingold to treat ADHD, eliminates foods containing salicylates, on the theory that salicylic acid can aggravate ADHD symptoms in people who are sensitive to it. Critics of that theory, including dietitian Joanne Larsen, say the scientific evidence is very weak, that some of the foods the Feingold Diet eliminates don't actually contain salicylates, and that eliminating fruits and other healthful foods could put kids at risk of vitamin C deficiency.
Gluten
Gluten is a combination of proteins found in wheat, rye, barley. Some people have celiac disease, in which the immune system responds to gluten as though it's a threat. It can damage the gut and cause a variety of symptoms, including neurological disorders. Italian researchers reported in the November 2006 issue of the "Journal of Attention Disorders" that in 132 children and adults with celiac disease, ADHD-like symptoms improved dramatically after 6 months on a gluten-free diet. If you suspect your child has a gluten intolerance, consult her pediatrician.
Sugar
Although plenty of parents swear that sugar turns their kids into whirlwinds of energy, Vanderbilt University pediatricians reviewed 16 well-controlled studies and reported in the November 1995 issue of the "Journal of the American Medical Association" that sugar doesn't affect children's behavior. In fact, sugar (like other carbohydrates) causes the release of serotonin, a calming brain chemical. It certainly doesn't hurt to cut back on sugar, which contributes to cavities and is linked to obesity. Many foods rich in sugar also contain caffeine, artificial colorings and other additives that might contribute to hyperactivity in some children.
Protein
Some parents report that eating more protein, especially at breakfast and lunch, helps their children with ADHD focus better. From a scientific standpoint, that makes sense, according to an article in the August/September 2005 issue of "ADDitude" magazine. Dietary protein may help trigger the release of brain chemicals, such as dopamine, that help you feel more alert.
Fats
Research indicates that kids with ADHD might have low blood levels of some essential fats, including omega-3s, reported Israeli researchers from Safra Children's Hospital in an August 2009 review of the research published in the journal "Developmental Medicine and Child Neurology." Some open trials involving fish oil, evening primrose oil (an omega-6 fat) and/or flax oil (omega-3) reported improvement in ADHD symptoms. But the Israeli reviewers pointed out that in more tightly controlled studies, EFA supplements haven't lived up to that promise. More research is needed.
References
- "Journal of the American Medical Association": The effect of sugar on behavior or cognition in children. A meta-analysis.
- "Journal of Attention Disorders": A preliminary investigation of ADHD symptoms in persons with celiac disease.
- Salicylates and the Feingold Diet
- Hyperactivity & ADHD - Ask the Dietitian
