KANSAS CITY, Mo. – Public smoking bans do more than just clear the air in offices, bars and restaurants – they lead to quick and dramatic declines in heart attacks.
Two teams of researchers came to this conclusion after independently examining evidence from more than a dozen locales in the United States, Canada and Europe that had enacted smoking restrictions.
Not only was the drop in heart attacks almost immediate, the declines tended to be greater the longer the bans were in place, the researchers found.
After smoking restrictions went into effect, heart attack rates dropped an average of 26 percent in a year, one study found. After three years, heart attack rates were down by an average of 36 percent, according to the other study.
“We’re confident that the benefit is real,” said David Meyers of the University of Kansas Medical Center, lead author of one of the studies. “The effect of smoke on heart attack is huge.”
Meyers estimated conservatively that a nationwide public smoking ban would prevent as many as 156,400 heart attacks a year. Nonsmokers would benefit by limiting their exposure to secondhand smoke. Smokers would have a greater incentive to quit or cut back.
“I am embarrassed that the U.S. has not passed a national smoking ban, and yet Scotland, Ireland, Italy and France did,” Meyers said. “But those countries aren’t big tobacco producers, so it was politically easier.”
As of last year, 23 states and the District of Columbia had enacted comprehensive smoking restrictions, according to the American Lung Association.
Meyers’ study, which he did with colleagues John Neuberger and Jianghua He, is in the latest issue of the Journal of the American College of Cardiology.
Also newly published in Circulation, the American Heart Association’s journal, is a study by researchers at the University of California, San Francisco, that looked at much of the same data and came to similar conclusions.
As recently as four or five years ago, claims that smoking restrictions yielded health benefits were controversial, said James Lightwood, co-author of the Circulation study.
“Now we’re getting a consistent picture,” Lightwood said. “The encouraging thing about the Meyers study and ours is apparently if you take the same data, the signal is so strong that people get almost the same result.”
Evidence linking smoking restrictions to lower rates of heart attack has been mounting for years. One startling study in Helena for example, found that the annual heart attack rate dropped 40 percent after the city banned public smoking. After a court suspended the ban, the rate shot up again.
But doubts about the health benefits have persisted because studies of different locales with smoking restrictions have yielded widely diverging results, from big drops in heart attack rates to little or no change, or even a small increase in heart attacks.
By analyzing trends in the data, the two research teams discovered that the differing results were due largely to variations in time periods covered by the studies. Some studies measured heart attack rates just a few months into a smoking ban; others examined a period of several years.
Heart attack rates decline so soon after smoking restrictions are in place because tobacco smoke’s ill effects work quickly on the heart by restricting blood flow and the supply of oxygen and by making blood more likely to clot.