There’s something about beer that makes it hard to have just a sip.
Recent research says that even the smallest taste of beer floods our brains with the neurotransmitter dopamine, prompting us to want the rest of the pint.
Dopamine plays many roles in the brain, but is most often associated with motivation, including reward-seeking behavior, drug abuse, and addiction.
Indiana University School of Medicine researchers say that people with close relatives who suffer from alcoholism have a stronger surge of dopamine when they taste beer, leading scientists to believe the response could be an inherited risk factor for alcoholism.
Years of research have linked dopamine levels to addiction, but there’s still debate about just what part it plays. Some neuroscientists contend that dopamine plays a critical role in stimulating the cravings of an addict, flooding the brain when an alcoholic sees a bar, for example.
Testing Beer’s Effect on Dopamine
The Indiana researchers used positron emission tomography (PET) to scan the brains of 49 men, once after they tasted beer and again after they tasted Gatorade.
Given a tablespoon of their preferred beer over a 15-minute period, research subjects’ PET scans showed a positively Pavlovian response: dopamine levels in the brain began to surge. Because such small amounts of beer were consumed, researchers say the alcohol itself couldn’t have spurred the dopamine production.
“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 Kareken, neurology professor and deputy director of the Indiana Alcohol Research Center, said in a press release.
Kareken also said those subjects with a genetic predisposition to alcoholism—i.e. a close relative with the disease—experienced a greater spike in dopamine than those without an alcoholic relative.
After the brain scans, research subjects reported an increased craving for beer, even though some thought the Gatorade tasted better.
The Indiana University study was published this week in the journal Neuropsychopharmacology.
More on Addiction
The Indiana study builds on a body of evidence exploring how the brain copes with addiction.
A previous study by researchers at the University of California, San Diego, found that just the sight and smell of alcoholic beverages can trigger a dopamine response in the brain. These findings show that the genetic predisposition to alcoholism is powerful and far from fully understood.
That’s why treatment programs like Alcoholics Anonymous (AA) preach total abstinence from alcohol, instead of a scaled-back approach. Research has confirmed that programs like AA benefit the majority of people in addiction treatment.
Besides genetics, scientists continue to compile known risk factors for addiction. We know that environment, the age at which a person begins using, the drug of choice, and the drug delivery method can all play a part. In many cases, addiction may stem from the desire to self-medicate another disorder, such as depression.
Learn more about addiction at Healthline’s Addiction Center.