Previous studies have focused on the physical effects of food, on conditions such as asthma, eczema and gastrointestinal problems. So where are the studies on the effects of food on the brain? The most recent study, published in The Lancet, February of this year by Pelsser, etc. (2011) investigated the effects of a restricted diet on behaviour of children with ADHD and differentiated between non-allergic and allergic mechanisms in food induced ADHD.
Children aged 4-8 years old who were diagnosed with ADHD, with no prior or current remedy, were separated into two groups. One group was given a restricted diet of foods limited to rice, meat, vegetables, pears and water with potatoes, wheat and fruits. The control group was maintained on a healthy diet.
Forty percent of children (40%) on the restricted diet showed significant improvement in their behaviour during the 5 week trial, in comparison to no improvements shown in children in the control group. The children who responded positively to the restricted diet were then re-introduced with either high or low IgG foods.
Sixty four percent (64%) of the children showed a significant behavioural relapse with the re-introduction of particular foods. The study found no direct relationship between the levels of IgG foods and the reduction of ADHD symptoms, however there was a positive relationship between a restricted diet and improvement in behaviour in children with ADHD and Oppositional Defiant Disorder. The study concluded that children who showed significant improvement in behaviour after a dietary intervention were most likely presenting with allergy-induced ADHD. The study recommended that all children with ADHD or ODD be placed on an elimination diet in order to define the foods that lead to allergy induced ADHD and other behavioural symptoms.
Effects of a Restricted Elimination Diet on the Behaviour of Children with Attention-Deficit Hyperactivity Disorder (INCA Study): A Randomised Controlled Trial.
Lidy M Pelsser, Klaas Frankena, Jan Toorman, Huub F Savelkoul, Anthony E Dubois, Rob Rodrigues Pereira, Ton A Haagen, Nanda N Rommelse, Jan K Buitelaar. The Lancet February 5, 2011; Vol. 377: 494-502.