Taste of beer alone triggers happy brain chemicals

Merely a small taste of beer is enough to trigger a chemical associated with the brain’s pleasure and reward centres, but is also linked with alcohol and drug addiction, a new study suggests.

Researchers at the Indiana University School of Medicine found that dopamine levels increased in men who consumed such a small amount of beer that the chemical boost could not be explained by the presence of alcohol.

For their study, the researchers administered positron emission tomography, or PET, scans to 49 men on two occasions: once when they tasted beer and another time when they tasted Gatorade.

The scans showed a large spike in dopamine after the men tasted the beer compared to when they sampled the Gatorade. As well, the dopamine boost was more pronounced in the men who reported a family history of alcohol addiction.

The researchers said the men received such a small amount of beer, 15 millilitres over a 15-minute time period, that they could taste it without experiencing any effects associated with alcohol consumption.

"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 centres," study co-author David A. Kareken, professor of neurology at the IU School of Medicine and the deputy director of the Indiana Alcohol Research Center, said in a statement.

The study was published in the online edition of the journal Neuropsychopharmacology.

The researchers point out that previous studies have long supported a link between dopamine and addiction, though the exact role the chemical plays is unclear.

Tastes, smells and visual cues that are associated with intoxication are known to spark cravings and to trigger relapses among recovering alcoholics, and dopamine is suspected to play a role in these cravings.

In addition to the dopamine boost, participants in the IU study also reported that they craved beer more after tasting it, but did not report the same after tasting the Gatorade.