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Oct. 15, 2009 -- Even limited exposure to secondhand smoke can increase the odds of heart attacks in people who have heart disease or are at risk, an expert panel report commissioned by the CDC confirms.
Another major finding by the panel: Smoking bans work.
“The report confirms that eliminating smoking in workplaces, restaurants, bars, and other public places is an effective way to protect Americans from the health effects of secondhand smoke, particularly on the cardiovascular system,” CDC Director Thomas R. Frieden, MD, MPH, says in a news release.
The Institute of Medicine (IOM) panel reviewed the research examining the impact of smoking bans on cardiovascular risk and the relationship between secondhand smoke and heart disease.
Panel members discussed their findings in a news conference, telling reporters that no single study was without its flaws but taken as a whole the research shows that secondhand smoke can cause heart attacks.
Laboratory studies show that even minimal exposure to secondhand smoke can increase blood clotting and constrict blood vessels, two major risk factors for heart attacks.
“If you have heart disease, you really need to stay away from secondhand smoke. It is an immediate threat to your life,” physician and smoking researcher Neil Benowitz, MD, of the University of California, San Francisco, said at the news conference.
He added that because many people don’t know they have heart disease until they have a heart attack, anyone could be at risk.
“Even if you think you are perfectly healthy, secondhand smoke could be a potential threat to you,” he said.
Many of the panel’s findings echo those of another major report on secondhand smoke, released by the U.S. Surgeon General in 2006.
The Surgeon General concluded that secondhand smoke exposure is responsible for tens of thousands of heart-disease-related deaths each year.
Both reports found that even brief exposure to secondhand smoke can cause immediate harm and both found smoking bans to be effective.
According to the CDC, 27 states still did not have comprehensive smoking bans in place as of June 2009.
The panel reviewed 11 studies examining the impact of smoking bans on heart attacks. All showed smoking bans to be associated with a reduction in heart attacks, but the range of the reduction varied widely from study to study -- from 6% to 47%.
The IOM report calls for new research specifically designed to better estimate the effect of smoking bans on cardiovascular events like heart attack and stroke.
It is now clear that secondhand smoke hurts the heart, but the size of the risk is not so clear.
Several studies suggest that secondhand smoke exposure increases a nonsmoker’s risk for heart disease by 25% to 30%. But the panel concluded there is not enough evidence to quantify the risk.
It is also now clear that wider implementation of laws banning smoking from public places could save lives, Friedman noted in his statement to the media.
Nearly three out of four U.S. adults have at least one major risk factor for heart disease, yet only 40% of Americans live in areas with comprehensive state or local laws banning smoking in public places.
“The only way to protect nonsmokers from the dangerous chemicals in secondhand smoke is to protect workers and the public through comprehensive smoke-free laws,” he noted.
The Institute of Medicine, which is the health research arm of the National Academy of Sciences, was established in 1970 with the goal of providing objective, evidence-based advice on major health matters.