The study, appearing in the February issue of the American Journal of Psychiatry, extends and supports earlier work in rodents showing that preference for sweeter solutions reliably predicts the propensity to consume alcohol.
In the human research, the first of its kind published, scientists asked 20 abstinent alcoholic men to taste five sugar solutions. The solutions ranged from not sweet at all to very sweet, with the strongest being more than twice as sweet as the soft drink Coca-Cola Classic. Each drink was given five times in random order.
Sixty-five percent of alcoholics preferred the sweetest solution compared to only 16 percent of non-alcoholics. All subjects were able to distinguish among the different concentrations.
Authors of the report are Drs. Alexey B. Kampov-Polevoy, research fellow; James C. Garbutt, associate professor; and David S. Janowsky, professor, all of psychiatry and all affiliated with UNC-CH's Skipper Bowles Center for Alcohol Studies.
"Sweet liking is a basic pleasurable reaction that may be seen in humans and other mammals within minutes after birth," Kampov said. "Disturbance in pleasurable response to sweets may reflect a dysfunction in the brain's system of positive reinforcement, which may also be involved in development of alcoholism."
The UNC-CH scientists have been exploring the relationship between liking sweets and alcohol craving for more than 10 years, he said. In animals, consumption of sweets, whether sugar or the artificial sweetener saccharin, may not only accurately predict the propensity to drink alcohol long before the first drink, but also significantly suppresses alcohol intake as well.
"This latter finding is of interest given the advice found in the early writings of Alcoholics Anonymous that eating and drinking sweets allays the urge to drink," said Kampov, a physician instrumental in bringing AA to the former Soviet Union in the late 1980s. "Unfortunately, this observation never made it to the medical textbooks."
The researchers hope to design a way to predict who is at greatest risk of developing alcoholism.
"Perhaps the benign and inexpensive sweet test, which takes only 10 minutes to perform, may be a first step in developing such a test," says Kampov. "This test could be used to screen youngsters to detect those with a predisposition to alcoholism, which might allow early education and prevention rather than waiting until alcoholism develops."
A continuing study at the Bowles Center indicates combining preference for sweets with certain personality features increases the test's predictive value, Kampov said.
"There are very few markers for alcoholism, and none are perfect," Janowsky said. "Obviously, a lot of people who are not and never will be alcoholics like sweets. Such a test may help us better understand who might be at risk, however, and intervene early to help them avoid alcohol dependence."
Further study of the effects of sweets on alcohol intake may lead to better treatments for alcoholism, such as special diets for recovering alcoholics, he said. The new finding is a provocative clue suggesting it may be possible to turn off alcohol craving with the help of sweets or by controling the mechanisms that make both alcohol and sweets desirable to some people.
The Bowles Center's mission is to search for the causes of alcoholism, to understand the impact of alcohol on different systems of the body and to discover new treatments for alcoholism.
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Note: Kampov can be reached at (919) 966-0751 or 966-5678; e-mail:kampov@med.unc.edu. Janowsky's numbers are 966-3365 (w) or 942-7941 (h).