Sweet tooth, rotten kid: a theory gone sour.

Sweet tooth, rotten kid: A theory gone sour

A new study disputes the notion that overindulgence in sweets predisposes a child to a life of disruptive behavior.

Seeking a link between sugar intake and behavior, researchers compared the consequences of eating either sugar or an artificial sweetener in high school students and juvenile delinquents. Surprisingly, their findings hint that for some delinquents a spoonful of sugar may actually improve behavior.

A substantial body of anecdotal evidence has suggested a causal link between antisocial behavior and heavy consumption of sugary foods. In one of the best-known examples, San Francisco killer Dan White blamed chronic overconsumption of Hostess Twinkies for the loss of judgment that in 1978 led him to gun down the city's mayor, George Moscone, and City Supervisor Harvey Milk. Some correctional facilities have removed their snack machines and desweetened their menus in an attempt to minimize behaviors associated with criminality, such as hyperactivity. Yet few well-controlled experiments have directly assessed the purported ties between sugar intake and behavior, and none has proved a link.

Now, in the August PEDIATRICS, researchers at the University of Wisconsin-Madison report results from the first study comparing the effects of different sweeteners on criminally delinquent and nondelinquent male adolescents.

Jo-Anne Bachorowski (now at the University of Colorado at Denver), Dian A. Gans (now at the University of Hawaii-Manoa), Joseph P. Newman and their colleagues administered neuropsychological tasks to 115 delinquents and 39 non-delinquents after giving them breakfasts sweetened with either sucrose or the artificial sweetener aspartame. The tests measured motor endurance, coordination, concentration, short-term memory and hyperactivity. The researchers also rated each individual for 32 mood and behavior variables and administered tests measuring cognitive function and behavioral disturbance. Each individual went through two rounds of testing -- one for each kind of breakfast.

The results provide "no support for the contention that sucrose ingestion compromises behavior" among delinquents or nondelinquents, the researchers report. And contrary to popular lore, the most hyperactive, destructive and behaviorally disturbed delinquents "demonstrated better performance after the sucrose than after the no-sucrose breakfast," they say.

The team also tested the controversial claim that aggressive, antisocial behavior can result from a metabolic abnormality called reactive hypoglycemia -- a short-term overreaction to sugar consumption, temporarily lowering blood glucose levels.

Oral sucrose-tolerance tests given to 137 delinquent and 41 nondelinquent teenagers show no greater incidence of reactive hypoglycemia among delinquents than among nondelinquents, the researchers report. But the tests do reveal significant differences in the rates at which the two groups metabolize sugar, Newman told SCIENCE NEWS. Citing these findings and unpublished research, Newman proposes that some delinquents suffer from inadequate regulation of blood sugar levels and may benefit from somewhat higher amounts of ingested sugar. He makes the unorthodox suggestion that sweets may represent a behavior-enhancing compensation for a metabolic defect in some delinquents.

Steven Schoenthal, a specialist in nutrition and behavior at California State University at Stanislaus, calls the new work "a valuable contribution," but he also points to some potentially confounding flaws. A longtime proponent of the sugar-behavior link, Schoenthal notes that the sucrose variation between the two test breakfasts was small compared with typical sucrose intakes by U.S. adolescents over an entire day. He suggests that sugar-related behavioral problems might well surface in similar studies involving larger variations in sucrose intake or examining the effects of sucrose in younger children.