Rocket fuel?

Every parent has seen it happen: take a group of young children, add sugar, then stand back and watch them bounce off the walls. But although many parents will find it hard to believe, sugar does not cause hyperactivity.

A 1996 review of 12 blinded studies, where no one at the time knew which kids had received sugar and which a placebo, found no evidence to support this notion. This is true even for children with ADHD or whose parents consider them to be sensitive to sugar (Critical Reviews in Food Science and Nutrition, vol 36, p 31)

In fact, one of these studies concluded that the sugar effect is all in parents’ minds. Parents and their 5 to 7-year-old “sugar-sensitive” children were split into two groups. The parents of one group were told their children had been given a large dose of sugar, while the others believed their kids were in the placebo group. In reality, all the children had been given sugar-free food. But when the parents watched their offspring at play afterwards, those who thought their kids were in the sugar group were more likely to rate their behaviour as hyperactive (Journal of Abnormal Child Psychology, vol 22, p 501).

“A doughnut can contain eight teaspoons of sugar”

Having said all that, sugar does affect kids’ brains, although in a surprising way. In one study, David Benton, a psychologist at Swansea University in the UK, found that in the half-an-hour or so after having a glucose drink, 9 to 11-year-old schoolchildren were better able to concentrate on tasks and scored higher in memory tests ( …