FRIDAY, July 30 (HealthDay News) -- Genetics may determine to
what extent you're swayed by the alcohol consumption of people
around you, new research suggests.
A study published in a recent issue of
Psychological Science found that people with a particular
genetic profile are far more likely than others without the gene to
drink more when they see someone else drinking heavily.
The finding is "quite meaningful" and "illustrates how much
genetics determines drinking patterns of individuals exposed to
other drinkers," said psychiatrist Dr. Marc Galanter of New York
University Langone Medical Center.
The study focused on different versions of a receptor for the
neurotransmitter dopamine, which controls feelings of pleasure.
Previous work had shown that one form of this receptor, which
contains a series of seven repeats of the same DNA sequence, is
associated with increased alcohol cravings in a variety of
To see if this DNA influenced reactions to social drinking
situations, Helle Larsen of Radboud University Nijmegen in The
Netherlands, recruited young adult volunteers -- allegedly to watch
and evaluate TV commercials between 4 and 9 pm in a setting that
resembled a typical Dutch pub.
However, Larsen's real objective was to see how many drinks each
person consumed during the study's break times.
The researchers also collected DNA samples from each participant
to see which version of the dopamine receptor they possessed.
Larsen and her colleagues found that people with the
seven-repeat version of the dopamine receptor were far more likely
than those with a different version to drink heavily when they saw
others doing so. The researchers suggest that individuals with this
particular genetic background are much more sensitive to others'
The results provide an interesting view into "the interaction
between genetics and reactions to environmental circumstances,"
It's not clear why this particular version of the dopamine
receptor might trigger increased responsiveness to others'
drinking, Larsen said, although some researchers have speculated
that people with this receptor are less sensitive to dopamine's
actions and so are likely to drink more to try to feel its
The authors also noted that seeing others drink lightly didn't
boost the urge to drink more in those with the receptor; only
witnessing heavy drinking triggered the desire.
While emphasizing that the results are preliminary and need
replication, the authors said the study setup simulated a real-life
situation, similar to that faced in a bar, restaurant or at a
Individuals with this genetic propensity may have to avoid many
social drinking situations if they wish to curb their own alcohol
intake, Larsen said.
"If you really don't want to drink or you know that it is difficult for you to refrain from drinking, maybe partly because of a genetic predisposition, then you should stay out of alcohol contexts, because these cues are so strong," Larsen said.
Social psychologist Henry Wechsler, of the Harvard School of
Public Health, cautioned that a couple of aspects of the experiment
may have influenced the results, however. The drinks offered during
the study were free, but "studies have shown that price has a
significant effect on drinking behavior," he said.
Also, it's possible that the participants' behavior was altered
because they thought of themselves as being under the watch of
"responsible scientists," he said. "They may consider themselves
protected from harms associated with heavy drinking."
There's more on problem drinking at the
U.S. National Institute on Drug Abuse.