Researchers have learned that rats overwhelmingly prefer water sweetened with saccharin to cocaine, a finding that demonstrates the addictive potential of sweets.
Offering larger doses of cocaine did not alter the rats' preference for saccharin, according to the report.
Scientists said the study, presented this week in San Diego at the annual meeting of the Society for Neuroscience, might help explain the rise in human obesity, which has been driven in part by an overconsumption of sugary foods.
In the experiment, 43 rats were placed in cages with two levers, one of which delivered an intravenous dose of cocaine and the other a sip of highly sweetened water. At the end of the 15-day trial, 40 of the rats consistently chose saccharin instead of cocaine.
When sugar water was substituted for the saccharin solution, the results were the same, researchers said.
Further testing the rat sweet tooth, scientists subjected 24 cocaine-addicted rats to a similar trial. At the end of 10 days, the majority of them preferred saccharin.