As there is no evidence for the effectiveness of IgG blood tests, researchers wanted to study the link between diet and behavior among children with ADHD.
Attention Deficit Hyperactivity Disorder (ADHD) is a neuro-developmental behavioral disorder characterized by inattentiveness, over-activity, impulsivity or a combination of all.
It is estimated that 5% children across the world are affected with ADHD. Such children often underachieve and find it hard to mingle and gel with their classmates or the peers and are difficult children to bring up and are often victims of neglect. .
Presently ADHD is treated with psycho-education, parent training, child behavioral interventions and some medication. Previous studies have suggested that food additives (colors and preservatives) may have some effect on the behavior of children with ADHD and there are suggestions that a diet restricted from these additives may help in treating these children. To diagnose such effect scientifically antibody test using - IgG blood tests should be performed to establish a relationship between ADHD and foods. It has been suggested that eating foods that induce high IgG levels would lead to substantial behavioral relapse, while eating foods that induce low IgG levels would not do the same.
Since there is no evidence for the effectiveness of these blood tests, researchers wanted to study the link between diet and behavior among children with ADHD. They also wanted to establish a link between allergic and non-allergic mechanisms in food induced ADHD. For this purpose they randomly assigned 4-8 year old children diagnosed with ADHD on a restricted elimination diet (diet group) or to a normal healthy diet (control group) for a period of 5-weeks. Thereafter every child’s IgG blood test was carried out. Children who showed more than 40% improvement were again assigned to a 4-week diet (second phase) in which high-IgG or low-IgG foods were added to the diet depending on the results of the blood test.
It was seen that 64% (32 out of 50) children benefitted from the restricted elimination diet. Re-introducing certain foods caused behavioral relapse in the children. However IgG blood tests did not help in determining which foods might have a deleterious behavioral effect. No substantial behavioral difference was noted in patients with high IgG or low IgG foods.
Thus scientists concluded that a strictly supervised restricted elimination diet is valuable for assessing whether ADHD is induced by food. However, the prescription of diets on the basis of IgG blood tests should be discouraged.
http://www.thelancet.com/journals/lancet/article
PIIS0140-6736%2810%2962227-1/abstract