Sugar causes hyperactivity in kids: A myth persisting for decades

The myth persists that sugar causes hyperactivity in children despite a lack of scientific evidence, says a pediatrician who put that belief to the test.

The work of Dr. MarkWolraich, a professor of pediatrics at the Oklahoma University Health Sciences Centerin Oklahoma City, has debunked the myth.

However,a non-scientific experiment by CBC News has essentially shown it's still alive.

• Myth or Science 3: You Are What You Eat, CBC-TV's The Nature of Things
• Celebrate Halloween by eating candy in moderation, say experts
• Sugar intake should be reduced to 5-10% of calories, WHO says
• Obesity: 'no silver bullet' but many promising weapons
• How 'toxic' is sugar?, CBC'sthe fifth estate

The experiment, over Halloween, aimed to seeif parents believedcandyled their children to bounce off the walls.

"They tend to not listen or get ready for bed if they've had too many desserts," said Pak Hum.

"She just can't focus," said Julie Snyder. "Can be any time, but definitely when she's on sugar."

For his part,Wolraichtried to establish a definite link between sugar and behaviour through observational and double-blind studies.

"When we finishedthe dietary study, it was published in theNew England Journal of Medicineand there was a fair amount on the national news,"Wolraichrecalled. "Within two or three years, they seemed to forget."

Reasons not to indulge in sweets

Wolraich'smeta-analysisreviewing 15 articles on sugar and artificial sweetener said the findings were clearer than any other analysis he had done on the subject.

Wolraichbelieves that when children are overactive, it often relates to changes in their routine, such as Halloween or birthday parties.

"If you have the belief their behaviour is worse and those areusually times when theyget large amount of sugar,it's not surprising youwould see the difference."

He points to another experiment where parents who thought their children were adversely affected by sugar tended to stand closer to them, and to be more demanding of them. "The parents' suggestion can be fairly strong in that case."

The other health reasons to avoid eating too much sugar still stand. For example, nutrition experts and dentists say candy is fine in moderation, but it is rich in calories and can be hard on oral health.