Smokers today may be more strongly influenced by genetic predispositions than in generations past, and that may be making it harder for them to quit, a new study suggests.
That’s not to say that our genes have changed, but rather that the makeup of the smoking population has. “In the past, when smoking rates were higher, people smoked for a variety of reasons,” co-author Fred Pampel, a sociology professor at University of Colorado, Boulder, said in a statement. “Today…smokers are more likely to be hard-core users who are most strongly influenced by genetic factors.”
Since the early to mid-1970s, when the first antismoking measures were being enacted, U.S. smoking rates have steadily declined. But in 2010, more than 19% of American adults were still smoking cigarettes, according to the latest government data. To gauge the extent to which genetic factors may be influencing smokers’ ability to quit, Pampel and colleagues studied patterns of tobacco use in pairs of twins.
The new study, published in the journal Demography, included 596 twin pairs — 363 identical, and 233 fraternal. The researchers used the participants’ responses to health questionnaires and tracked the twins’ smoking behavior between 1960 and 1980, a period during which the public perception of smoking changed.
The researchers found that among identical twin pairs, 65% of both twins quit within two years, if one twin quit first. By contrast, only 55% of fraternal twins managed to do the same — a statistically significant difference. The finding suggests that a genetic factor is at play, since identical twins share the exact same DNA, while fraternal twins do not.
“These days people don’t smoke as much for social reasons,” Pampel said. “They, in fact, face criticism for the habit, but tend to smoke because of their dependence on nicotine.”
Still, the research team did not investigate whether a specific gene variant could be related to nicotine addiction; indeed, no such gene has yet been identified.
The authors suggest that current policies to reduce smoking — like heavy tobacco taxes and bans on public smoking— might not work as well as they have in the past, because they tend to treat smoking as a choice rather than an addiction. These public-health efforts “may be effective in prodding social smokers with genetic resilience to quit, but may do less to help genetically vulnerable smokers quit,” said Pampel. The research team recommended emphasizing therapeutic quit-smoking approaches instead, like nicotine-replacement therapy and counseling.
It’s not news that cigarettes are addictive, but it may be helpful for smokers to know why some quit strategies may work better for them than others — especially on the Great American Smokeout.