Why beer makes you happy

Researchers claim that beer even without its alcoholic content has a similar effect on the human brain and triggers dopamine in the same way drugs and other alcoholic drinks do. Using positron emission tomography (PET), the researchers at Indiana University School of Medicine tested 49 men with two scans, one in which they tasted beer, and the second in which they tasted Gatorade.

The researchers were looking for evidence of increased levels of dopamine, a brain neurotransmitter that has long been associated with alcohol and other drugs of abuse. The scans showed significantly more dopamine activity following the taste of beer than the sports drink, moreover, the effect was significantly greater among participants with a family history of alcoholism.

'We believe this is the first experiment in humans to show that the taste of an alcoholic drink alone, without any intoxicating effect from the alcohol, can elicit this dopamine activity in the brain's reward centers,' David A. Kareken, Ph.D., professor of neurology at the IU School of Medicine and the deputy director of the Indiana Alcohol Research Center, said.

Kareken said that the stronger effect in participants with close alcoholic relatives suggests that the dopamine release in response to such alcohol-related cues may be an inherited risk factor for alcoholism. The participants got a very small amount of their preferred beer - 15 milliliters - over a 15-minute time period, enabling them to taste the beer without having any detectable blood alcohol level or intoxicating effect. Using a PET scanning compound that targets dopamine receptors in the brain, the scientists were able to assess changes in dopamine levels occurring after the participants tasted the liquids.

Results have been published online Monday by the journal Neuropsychopharmacology.