A man smokes a cigarette outside.
Smoking cessation programs have made it easier than ever to kick the habit. (For Spectrum Health Beat)

As the number of smokers in the United States dwindles, those who still light up are becoming less attached to the habit and more likely to try quitting, a new study has found.

These findings run counter to the theory of “hardening,” which has held that as smoking rates decline those who still smoke will be increasingly committed to their habit, said study author Margarete Kulik, a postdoctoral fellow with the Center for Tobacco Control Research and Education at the University of California, San Francisco.

“The assumption is as smoking prevalence decreases, those smokers who are left will be the hardcore smokers who are unable or unwilling to quit,” Kulik said. “We found out that there is not hardening. There is softening. There is actually more quitting, and people smoke less.”

The study was published online June 24 in the journal Tobacco Control.

Dr. Norman Edelman, senior scientific advisor for the American Lung Association, said the study reflects the success of U.S. anti-smoking policies.

Clean air laws have made it more difficult to smoke in public, cigarette taxes have made the habit more expensive, and education campaigns have convinced the public that smoking is harmful and repellant, he said.

At the same time, smoking cessation programs have made it easier than ever for smokers to get support as they try to quit their addiction.

“It’s conceivable we’ve reached a tipping point, and have really set in motion a cultural event in which smoking is not acceptable and not enjoyable,” Edelman said.

Smoking rates have declined significantly since 1965, according to the U.S. Centers for Disease Control and Prevention. Back then, about 42 percent of the adult population smoked; about 18 percent of American adults are cigarette smokers now, which amounts to some 42 million people.

In the study, researchers evaluated state-level survey data on tobacco use gathered between 1992 and 2011 by the U.S. Census Bureau.

The investigators found that for every 1 percent decrease in the fraction of the U.S. population that smokes:
• The number of smokers who try to quit increases by 0.6 percent.
• The percentage of smokers who successfully quit increases by about 1 percent.
• Cigarette consumption among remaining smokers decreases by 0.32 cigarettes a day.

“This goes to show that the policies that are in place right now are working,” Kulik said. “The perception of smoking is changing in the population, and smokers are feeling that influence.”

Anti-smoking policies have not been as effective in Europe, however. The researchers found that decreases in the smoking rate do not encourage European smokers to quit, and that overall cigarette consumption levels have remained stable there.

Kulik and Edelman argued that these findings undermine attempts by e-cigarette and smokeless tobacco companies to sell their products as a way of weaning people away from cigarettes.

“We’re making good progress without them,” Edelman said. “We don’t need them, and we don’t know the health effects or addictive potential of e-cigarettes.”

At the same time, the United States needs to keep up the pressure and either maintain or strengthen its anti-smoking policies, Edelman concluded.

“If so few people smoke that it’s not part of the culture, maybe it’ll just die out,” Edelman said. “But it doesn’t mean we should stop everything we’re doing. We can’t let up yet. Just because the goal line is in sight doesn’t mean we stop running.”