MONDAY, Sept. 21, 2009 (HealthDay News) -- Localities that ban smoking in bars, restaurants and other public places witness a quick drop in heart attacks, two new studies show.
The research -- which incorporated data from a total of 24 studies of smoking bans across the country -- found at least a 17 percent reduction in heart attacks one year after the bans had been enacted.
"That's when you lump all these studies together," said Dr. David G. Meyers, a professor of cardiology and preventive medicine at the University of Kansas and lead author of a report that will appear in the Sept. 29 issue of the Journal of the American College of Cardiology.
"One thing we looked at was the effect of duration," Meyers said. "The longer the study, the greater the beneficial effect. On average, after one year there was a 25 percent reduction in the risk of heart attack. The risk reduction got bigger the longer the ban was in effect."
The other study, published in the Sept. 21 issue of Circulation, found a 17 percent drop in heart attack rates after one year and about a 36 percent drop three years after smoking restrictions had been enacted.
It incorporated data from 13 studies in the United States, Canada and Europe. Meyers's research effort analyzed data from 11 studies of 10 public smoking bans in the same geographic regions.
Meyers said that the greatest benefit revealed in his study was seen in people younger than 50. Women seemed to benefit more than men, but for an unknown reason, he said.
Because the studies his group reviewed included localities with a total population of 22 million, "we can make a rather firm conclusion that smoking bans reduce the risk of heart attacks," Meyers said.
The results indicate that a nationwide ban on smoking in public places would prevent 156,400 heart attacks a year in the United States, the report in the cardiology journal said.
One scenario in particular appears to clinch the case, Meyers said. When officials in Butte, Mont., banned smoking in public places, the incidence of heart attacks decreased by 45 percent. A judge reversed the banning ordinance, and the incidence of heart attacks returned to the previous level, he said.
Smoking increases the risk of heart attacks and other cardiovascular problems in a number of ways -- by making artery-clogging blood clots more common, by reducing the amount of beneficial HDL cholesterol and by raising the possibility of dangerous heart rhythm abnormalities. Smokers double their risk for heart attacks, and secondhand smoke exposure increases the risk by 30 percent, the researchers said.
Smoking bans almost certainly decrease the risks for cardiovascular problems such as stroke and lung disorders such as emphysema, as well as lung cancer, said Dr. Steven A. Schroeder, director of the Smoking Cessation Leadership Center at the University of California, San Francisco, "but those decreases generally take a lot longer to take place." He wrote an editorial that accompanied the publication of Meyers's study.
Predictions that smoking bans will cause a disastrous drop in business for bars and restaurants generally don't come through, Schroeder said. "A lot of people don't like going into smoking restaurants and bars," he said. "The last haven of smoking is in gambling casinos."
And though many gamblers might not mind a smoky atmosphere, employees are inevitably exposed to the dangers of smoke, Schroeder said. A similar situation was faced by airline flight attendants in the 1970s and 1980s, he said. They eventually sued the airlines and won a settlement that has enabled them to establish a research institute on the dangers of smoking, Schroeder said.
New York City, which has had a smoking ban for several years, now proposes to extend that ban to city parks. Meyers said that seems like a good idea, though the immediate effect is uncertain.
"The dilutional effect of open air means there might not be enough smoke to make a difference," he said. "But only a tiny exposure to cigarette smoke can be dangerous. I would like to see everyone stop smoking, and I think a smoking ban in parks would help, but there is no scientific evidence to show that it would help."
The U.S. Centers for Disease Control and Prevention offers a report by the U.S. surgeon general on the dangers of secondhand smoke.