Dietary Control May Improve Attention Deficit Hyperactivity Disorder Symptoms
The condition has both genetic and environmental factors. The exact cause is not known though. Certain foods may be triggers for symptoms of ADHD. It has been found that a restricted elimination diet, or RED, i.e. one that eliminates certain foods may in fact help children with ADHD. In a group of young children with ADHD nearly two-thirds who followed a RED experienced a significant reduction in ADHD symptoms and oppositional defiant behavior. Going off the diet lead to worsening of the condition, i.e. relapse.
A diet restricted to certain foods including rice, white meat, vegetables and fruits was tested on children between the ages of 4 and 8 for five weeks. Wheat, tomatoes, oranges, eggs and dairy products were eliminated in the diet. The diet plan was individualised with each child given a customised meal plan. Not all children could stick on to the diet plans. Only 78% children completed the study. This group responded by having fewer symptoms of both ADHD and ODD "oppositional defiant disorder" -- a disorder in which the affected children express hostility and rebelliousness toward authority figures. Reintroduction of the offending foods leads to relapse.
The diet works better for younger children, ages 3 to 7. If there is no improvement in two to five weeks, it should be discontinued. A risk of malnutrition cannot be ruled out either. A favourable response would however mean that the child wouldn't require medications anymore.
Avoiding foods with artificial food colourings, flavours and sweeteners may help about 5% of children. Excess junk food can be detrimental.
Authors of the study suggest that dietary intervention should be considered in all children with ADHD. The researchers advocate willingness of parents to aid their children to follow a diagnostic restricted elimination diet for a 5-week period. Physician oversight is also mandatory. Children who react favourably to this diet should be diagnosed with food-induced ADHD. A food challenge test may further be done so as to identify the exact food trigger.
These findings from the Impact of Nutrition on Children with ADHD (INCA) study were published in the February 5 issue of The Lancet. The INCA study also suggests that the underlying mechanism of food sensitivity in ADHD (which could be related to genetic factors) is nonallergic. This meant that the use of blood tests to identify trigger foods is not advisable. Unlike previously thought levels of immunoglobulin G (IgG) antibodies were found to have no association with behavioral effects.
'A strictly supervised restricted elimination diet is a valuable instrument to assess whether ADHD is induced by food. The prescription of diets on the basis of IgG blood tests should be discouraged', concluded the authors.
Source: Pelsser LM, et al "Effects of a restricted elimination diet on the behaviour of children with attention-deficit hyperactivity disorder (INCA study): a randomised controlled trial" Lancet2011.