All it takes is a taste, say researchers from Indiana University, for the brain to react to beer by releasing a burst of the neurotransmitter dopamine, which acts as a reward for the brain.
Published in the journal Neuropsychopharmacology, the study administered 15 mililiters of beer to 49 adult men over the course of 15 minutes. As they did this, scientists observed changes in the men's brain chemistry with a positron emission tomography (PET) scanner, which measures levels of various molecules in the brain.
They then exposed the men to Gatorade and water, again watching the brain scanner.
Despite a wide range armong the study's subjects drinking habits, from social to heavy drinking, all of them showed a sudden increase in dopamine that was only present when they given beer.
What's more, those with first-degree alcoholic relatives showed on average a higher release of the neurotransmitter, demonstrating, according to the the study's authors, "that the response is strongest in subjects with a greater genetic risk for alcoholism."
The discovery, the researchers believe, may be a clue as to why some people are predisposed toward alcholoism and why it's harder to quit given that the immediate release of dopamine likely serves as a powerful driver of their cravings. What's more, the study could explain why people with a family history of alcoholism are twice as likely to experience it themselves.
A study published in 2003 demonstrated that visual cues, as well, can be powerful. The study showed teens who reported varying degrees of alcohol abuse images of alcoholic and non-alcoholic drinks. Those who reported being heavier drinkers showed a higher degree of brain activation when shown images of the former, compared to their peers who drank less.