Although traditional research has not come out in support of dietary treatment for ADHD, some parents and researchers still believe that diet is an important factor in the disorder’s treatment and prevention.
Particular theories include the idea that artificial colors or preservatives cause ADHD, or that it is due to a deficiency of omega-3 fatty acids or micronutrients.
After reviewing the research available for several diet-based theories of the cause of ADHD, the authors wrote: “A diet or dietary supplement that eases the symptoms of ADHD would be a boon for anyone living with this disruptive disorder. So far, though, the evidence provides only limited support for restrictive diets, avoiding preservatives or artificial food colorings, consuming more omega-3 fats, or taking specific vitamins or minerals.”
They said that when it came to examining the effect of artificial additives, “many of the studies were small or flawed” but cited the well-known Southampton study as a reason for reignited interest in the theory. The study, published in UK-based The Lancet, found a “mild but significant” link between six artificial colors and hyperactivity in children.
The authors of the Harvard Medical School review said that although parents might consider cutting artificial additives from their children’s diets, they should be aware that other studies have shown that parental expectations of behavioral change have a strong influence on what they actually perceive.
Deficiency in omega-3 fatty acids has also been singled out as a possible contributing factor to ADHD. This is because the fatty acids are known to affect transmission of the neurotransmitters dopamine and serotonin and because ADHD and omega-3 deficiency share some symptoms: Increased need to urinate and extreme thirst. However, the review’s authors concluded that omega-3 studies have also been flawed.
In addition, they said trials with supplementation of vitamins and minerals have also provided inconsistent results.
The authors concluded: “A healthful diet may reduce symptoms of ADHD by reducing exposure to artificial colors and additives and improving intake of omega-3 fats and micronutrients. But it certainly will improve overall health and nutrition and set the stage for a lifetime of good health.”
They recommend a balanced diet and plenty of physical activity. “The consensus on a sensible approach to nutrition for children with ADHD is the same recommended for all children,” they said.