Restricted diets can help children with ADHD, study suggests

Different foods trigger different behavioural problems and should be monitored, according to paper in the Lancet

Sarah Boseley, health editor

The Guardian, Friday 4 February 2011

 Ritalin is widely used to treat children diagnosed with ADHD, but a paper in the Lancet suggests changing diet may be as effective. Photograph: Murdo Macleod

Children with attention deficit hyperactivity disorder (ADHD), who are impulsive, inattentive and unable to sit still, should be put on a restricted diet for several weeks to establish whether particular foods are the cause, scientists say today.

Certain foods and additives can worsen the behaviour of some children, although guidelines from the National Institute for Health and Clinical Excellence (Nice) say there is no proof that cutting out fatty acids, food colourings or additives can help.

A paper published today in the Lancet medical journal establishes that food is responsible for ADHD children's erratic and difficult behaviour in many cases, although it is likely that different foods trigger behavioural problems in different children. The findings are likely to be welcomed by those who are concerned about the amount of drug treatment given to children with ADHD.

Researchers from the Netherlands put 50 children with ADHD on a "restricted elimination diet" consisting of foods with the least possible risk of allergic reaction – a combination of rice, meat, vegetables, pears and water – which was tailored to the preferences of each child. A second group of 50 children were not put on a diet, but their parents were given advice on healthy eating and asked to keep a diary of everything their child ate.

The behaviour of 78% of the 41 children who completed the five-week restricted diet phase improved, while the behaviour of those who were not on a special diet remained the same.

Researchers then tried adding particular foods high in immunoglobulin G (IgG), antibodies known to trigger allergic responses, to the restricted diet. They subsequently added foods that were low in IgG – to find out whether blood tests for the antibodies could be used to identify foods that trigger ADHD. However, 63% of the children relapsed and there was no difference in the response to low IgG or high IgG foods.

The researchers conclude that – although food sensitivity plays a part in ADHD, it is not caused by an allergic reaction.

"We think that dietary intervention should be considered in all children with ADHD. This provided that parents are willing to follow a diagnostic restricted elimination diet for a 5-week period, and that expert supervision is available," say Professor Jan Buitelaar of the Radboud University Nijmegen Medical Centre and Dr Lidy Pelsser of the ADHD Research Centre in Eindhoven.

"Children who react favourably to this diet should be diagnosed with food-induced ADHD. They should enter a challenge procedure to define which foods each child reacts to, increase the feasibility and minimise the burden of the diet. In children who do not show behavioural improvements after following the diet, standard treatments such as drugs, behavioural treatments, or both should be considered."

British experts welcomed the findings. "This study provides further evidence for the potential value of dietary approaches to the treatment of ADHD," said Professor Jim Stevenson of the University of Southampton. "It is a condition that disrupts family life, interferes with the child's ability to sustain friendships with other children and places the child at risk of longer term problems with attainment in school. Many parents are reluctant to use a drug treatment and it is important that alternatives such as the few foods approach can be shown to be effective."

But professor David Daley at Nottingham University's institute of mental health said there was more work to do. "Scientifically, I think this paper offers excellent evidence about another possible underlying cause of ADHD, but it would be premature to conclude such dietary intervention would be of any clinical benefit to children with ADHD and their parents. We need to know more about how expensive the intervention is, how motivated parents must be to make it work, and how easy it is for parents to get their child to stick to the diet," he said.

(www.guardian.co.uk)