A Princeton University scientist has found what many dieters already knew: Sugar can be addictive - just like drugs.
Professor Bart Hoebel and his team in the Department of Psychology and the Princeton Neuroscience Institute have been studying signs of sugar addiction in rats for years - and have demonstrated that sugar can be an addictive substance, wielding its power over the brains of lab animals in a manner similar to many drugs of abuse.
Until now, the rats under study have met two of the three elements of addiction. They have demonstrated a behavioral pattern of increased intake and then showed signs of withdrawal. His current experiments captured craving and relapse to complete the picture.
"If bingeing on sugar is really a form of addiction, there should be long-lasting effects in the brains of sugar addicts," Hoebel said.
"Craving and relapse are critical components of addiction, and we have been able to demonstrate these behaviors in sugar-bingeing rats in a number of ways," the expert added.
At the annual meeting of the American College of Neuropsychopharmacology in Scottsdale, Ariz., Hoebel will report on profound behavioral changes in rats that, through experimental conditions, have been trained to become dependent on high doses of sugar.
"We have the first set of comprehensive studies showing the strong suggestion of sugar addiction in rats and a mechanism that might underlie it," Hoebel said.
The findings eventually could have implications for the treatment of humans with eating disorders, he said.
Lab animals, in Hoebel's experiments, that were denied sugar for a prolonged period after learning to binge worked harder to get it when it was reintroduced to them. They consumed more sugar than they ever had before, suggesting craving and relapse behavior. Their motivation for sugar had grown.
"In this case, abstinence makes the heart grow fonder," Hoebel said.
The rats drank more alcohol than normal after their sugar supply was cut off, showing that the bingeing behavior had forged changes in brain function. These functions served as "gateways" to other paths of destructive behavior, such as increased alcohol intake. And, after receiving a dose of amphetamine normally so minimal it has no effect, they became significantly hyperactive.
The increased sensitivity to the psychostimulant is a long-lasting brain effect that can be a component of addiction, Hoebel said.
The data to be presented by Hoebel is contained in a research paper that has been submitted to The Journal of Nutrition.