Food may not be the major cause of hyperactivity in children. Genetics, brain function and parental actions such as smoking may be just as important.

ADHD (attention deficit/hyperactivity disorder) has a strong genetic link, with half the children born of parents with diagnosed ADHD likely to develop the disorder themselves. Chemical imbalances in the brain are also involved and studies have found that children with the condition have on average 4% smaller brains. Genes may interact with environmental toxins such as alcohol in the womb, lead, and parental smoking to cause later problems with attention span.

A review of scientific evidence found only a minority of children were actually affected by what they eat. A combination of food, genetics and environmental toxins are more likely to be involved, with no single factor to blame.

Foods which might affect behavior, in particular table sugar were studied. No adverse effects were seen in children who had a sugary drink versus a drink with artificial sweetener. Parents often believe their children’s diet is making them hyperactive and think changes in the food provided is the answer to the problem. However changing your child’s diet is not likely to settle their over active behavior.

Professor David Benton, who specialises in eating behavior and who carried out the study said ‘Parents say after an hour of eating sugary foods that their child is distracted and fidgety, but studies show that this is more what the mother expects to see and not what’s really going on’. He added ‘the origin of the idea that sugar is responsible for hyperactivity seems to be purely based on the fact that sugar is a source of energy, as are other carbohydrates. Foods like wheat and dairy can often cause food intolerance in children, but this is a completely different reaction of the immune system.’

This review which was carried out at the University of Wales, Swansea is published in the May issue of the journal Critical Reviews in Food Science and Nutrition. It comes at a time when the Food Standards Agency is looking at other causes of hyperactivity in children with a call to remove certain additives in foods.

Up to 9% of children in the U.K. have been diagnosed with ADHD. Problems are usually seen at around 4 years of age when the child may become easily distracted, fidgety, and impulsive over a long period of time.