The taste of beer, without its alcoholic effects, may be enough to trigger the release of the pleasure chemical dopamine in the brain, a study finds.
To see how the taste of beer affects the brain, researchers gave a group of men tiny tastes of beer, and as the men sipped the beer, the researchers scanned the men’s brains. After a taste of beer, the men's brains showed a notable release of dopamine, a brain chemical associated with the pleasurable experience of consuming alcohol and other drugs. The effect was even greater among men who had a family history of alcoholism.
The findings are not surprising, scientists say, but having a way to assess predisposition to alcohol abuse could be useful.
"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," the study's senior author, neuroscientist David Kareken of the Indiana University School of Medicine, said in a statement. The findings were detailed online today (April 15) in the journal Neuropsychopharmacology.
Dopamine, a brain chemical widely associated with pleasure, has long been linked to the consumption of alcohol and other drugs. Sensory cues — such as tastes, smells or the sight of a bar — can elicit cravings to drink and cause relapses in recovering alcoholics. Dopamine may be critically involved in such cravings, scientists believe. [11 Interesting Facts About Hangovers]
In the study, researchers gave 49 male volunteers a tiny taste (half an ounce, or 15 milliliters) of their favorite beer over the course of 15 minutes — enough to taste the beer but not enough to cause a change in blood-alcohol level or intoxication. At other times, the volunteers were given a sports drink or water, for comparison.
To study the effect of beer's taste on dopamine receptors, the researchers scanned the volunteers' brains using Positron Emission Tomography, which uses the radiation emitted by a radioactive chemical to produce a 3D image of the brain.
The scans revealed higher increases in dopamine after the men tasted beer compared with tasting the sports drink or water — suggesting that the taste of alcohol is enough to prompt a pleasurable response in the brain. The men also reported higher beer cravings after tasting beer than water or the sports drink.
Furthermore, the men who had a family history of alcoholism showed an even greater spike in dopamine levels after they tasted the beer, so the dopamine response may be a heritable risk factor for alcoholism.
"This paper demonstrates that taste alone impacts on the brain functions associated with desire," Peter Anderson, a professor of substance use, policy and practice at Newcastle University, U.K., said in a statement. But Anderson noted that “With regard to the family history effect, this is quite difficult to assess and know what it means so we can’t be too sure of an effect or how strong it might be."
The effects of the alcohol itself on the brain, and not just the taste, could not be ruled out, Anderson added.