It's been known for some time that alcohol in beer, wine and liquor, consumed in large enough quantities, can trigger the release of dopamine in the brain. But a new study reveals that the mere taste of beer, in the absence of any alcoholic mechanism, can touch off a dopamine surge, as well.
A group of researchers led by David Kareken of Indiana University came to the finding, published today in the journal Neuropsychopharmacology, by giving tiny amounts of beer to 49 adult men and tracking changes in their brain chemistry with a positron emission tomography (PET) scanner, which measures levels of various molecules in the brain. They chose participants with varying levels of typical alcohol consumption—from heavy drinkers to near-teetotalers—and even tested them with the beer they reported that they drank most frequently. Because they used an automated system to spray just 15 milliliters (about half an ounce) of beer on each participant’s tongue over the course of 15 minutes, they could be sure that any changes in brain chemistry wouldn’t be due to intoxication.
The effect was significant. When the men tasted the beer, their brains released much higher levels of dopamine within minutes, compared to when the same test was conducted on the subjects at other times with both water and Gatorade. They were also asked to rate how much they “craved” a beer at several points during the experiment, and perhaps less surprisingly, their cravings were generally much higher after tasting beer than Gatorade or water.
Intriguingly, participants with a family history of alcoholism showed higher dopamine levels after their half-ounce spritz of beer than those without (including heavy drinkers with no family history). The findings could provide insight into the mechanisms underlying predisposition to alcoholism and other addictive habits.