The study, which was presented last month by lead researcher Professor Bart Hoebel of Princeton University, claimed to show that sugar-bingeing rats experience changes in brain patterns and behaviour similar to those seen in drug addicts. Hoebel said that the study could have implications for the treatment of eating disorders such as bulimia, and provide insight into the nature of addiction.
However, independent researcher Professor David Benton, who specialises in dietary influences on mood and cognitive function, disagrees.
He told ConfectioneryNews.com that changes in the brain caused by sugar consumption, as with food consumption in general, differ from those caused by drug abuse.
He said: “Only when sugar is administered in a highly prescribed and unusual manner is it reported that signs of addiction occur.”
Predictions
Benton also suggested that elements of the rat study did not correlate with the reality of human eating disorders. For example, Hoebel’s rats had food withheld before subsequent bingeing, while in people, dieting is not necessarily a precursor to the development of bingeing. The conditions could also be seen as an assumption that bingeing entails a preference for sweet foods, or that dietary style is more important than socio-economic factors, he claimed.
“It is possible to make various predictions that would follow if the rat-model of Hoebel was an homology of human binge eating disorders,” said Benton. “…A review of the human scientific literature fails to support any of these predictions.”
Hoebel, who has been studying sugar addiction for a decade, acknowledged that more research needs to be carried out to explore the implications for people, but said: “Our work provides links between the traditionally defined substance-use disorders, such as drug addiction, and the development of abnormal desires for natural substances. This knowledge might help us to devise new ways of diagnosing and treating addictions in people.”
Relevance of animal studies
Benton, on the other hand, remains sceptical of the relevance of Hoebel’s research to human disorders.
“There is a need to move from the rat to the human condition,” he said. “The existing literature, however, suggests that the rat data are unlikely to be confirmed in humans…There is a place for animal studies but they can no more than generate hypotheses that may or may not be confirmed in humans.”
Benton added that research has shown socio-economic and psychological factors to play a significant role in the development of eating disorders and obesity which do not figure in the life of a rat.