Heart Disease Studies

In the body text of this page, you will find information on studies that have documented the adverse health effects of secondhand smoke exposure on the heart.

In the orange Related Topics box at the top right of the page, you will find studies documenting the impact of smokefree air laws on heart attack rates.

A study published in June 2010 in the Journal of the American College of Cardiology concluded that nonsmokers exposed to higher levels of secondhand smoke were twice as likely to die from heart disease as nonsmokers with lower exposure levels.

A study published online ahead of print in May 2009 in the journal Tobacco Control, concluded that never-smoking women in Hong Kong who were exposed to secondhand smoke in their homes had an increased risk of heart disease.

In a January 2009 study published in the American Journal of Preventive Medicine, the authors estimated that, at 1999-2004 levels of exposure, secondhand smoke caused between 21,800 and 75,100 coronary heart disease (CHD) deaths, and between 38,100 and 128,900 myocardial infarctions (MIs) each year.

A study published online ahead of print on December 10, 2008 in the journal Preventive Medicine estimated the probable decreases in acute myocardial infarction (AMI) due to implementation of a smokefree air law. The authors wrote that, "After evaluating several possible combinations of these parameters, we found that AMI reductions of 5-15% seem likely."

In a November 2008 editorial in the American Journal of Cardiology [102(10): 1421-1424], authors concluded that studies on the impact of smokefree laws on cardiovascular disease all had limitations, most notably their ecologic study designs, short-term follow-up, and lack of exposure information. Nonetheless, when taken in aggregate, these studies offer consistent evidence that smokefree laws are associated with a reduction in the risk for AMI in the general public, particularly in nonsmokers.

A study conducted by the Masschusetts Department of Public Health and the Harvard School of Public Health compared the impact of both local smokefree laws and the eventual passage of a statewide smokefree law on heart attack deaths in the state. The results show a steep decline in heart attack deaths started as Boston and most of its neighbors adopted smokefree laws. Enforcement of the statewide law beginning in mid-2004 coincided with a further reduction. From 2003 to 2006, heart attack deaths in Massachusetts plummeted 30 percent, significantly accelerating what had been a more modest long-term decline.

Click here to see a visual demonstration of how secondhand smoke exposure can impact your cardiovascular system.

Secondhand Smoke Poses Even Greater Risk for Heart Disease

A study published in the January 2009 issue of the American Journal of Preventive Medicine predicted that, "At 1999–2004 levels, passive smoking caused between 21,800 and 75,100 CHD deaths and between 38,100 and 128,900 myocardial infarctions annually. Treatment costs ranged from $1.8 to $6.0 billion per year. If recent trends in the reduction in the prevalence of passive smoking continue from 2000 to 2008, researchers predict that the burden would be reduced by approximately 25%–30%."

A study published in the May 6, 2008 issue of the Journal of the American College of Cardiology found that as little as 30 minutes of secondhand smoke exposure caused damage to the blood vessels of young adults. The lead author of the study, Christian Heiss, MD, stated, "These findings have significant public health implications and should raise further awareness of the negative side effects of even brief exposures to secondhand smoke. Our results help explain why there is a big immediate drop in heart attacks when smoke-free laws are passed."

In March 2008, research presented at the American Heart Association's 48th Annual Conference on Cardiovascular Disease Epidemiology and Prevention stated that secondhand smoke exposure in the home "appears to induce markers for heart disease as early as the toddler years." Judith Groner, M.D., lead author of the study, pediatrician and ambulatory care physician at Nationwide Children's Hospital and Research Institute in Columbus, Ohio, stated, "This is the first study that looks at the response of a young child's cardiovascular system to secondhand smoke."

In February 2007, a study published in the journal Circulation stated that, "Passive smokers appear to have disproportionately increased levels of 2 biomarkers of cardiovascular disease risk, fibrinogen and homocysteine. This finding provides further evidence to suggest that low-level exposure to secondhand smoke has a clinically important effect on susceptibility to cardiovascular disease."

The August 19, 2006 issue of The Lancet, published research from McMaster University in Ontario, Canada, which determined that all types of tobacco use or exposure -- smoking, chewing, or secondhand smoke -- increase a person's risk for heart attack. The study found that secondhand smoke exposure increased the risk of heart attack among both smokers and nonsmokers, and that people with 22 or more hours of SHS exposure per week have an approximately 45 percent higher risk.

In May 2006, the Canadian Journal of Physiology and Pharmacology published a study that concluded "Even 30 min of passive smoking rapidly impairs vascular endothelial function, which is associated with oxidative stress. Our data provide the pathophysiological insight for the recent epidemiological evidence about the increased risk of coronary heart disease among nonsmokers exposed to passive smoking."

In May 2005, Circulation, the Journal of the American Heart Association, published a literature review of research into the "mechanistic effects of secondhand smoke on the cardiovascular system, emphasizing research published since 1995, and compared the effects of secondhand smoke with the effects of active smoking." The study concluded that "Secondhand smoke increases the risk of coronary heart disease by [approximately] 30%. This effect is larger than one would expect on the basis of the risks associated with active smoking and the relative doses of tobacco smoke delivered to smokers and nonsmokers."

In June 2004, the British Medical Journal published a study that found that the risks of secondhand smoke exposure are even worse than previously thought. Exposure to secondhand smoke can increase the risk of coronary heart disease by 50-60%, twice the previous estimated risk. The study supports the multitude of previous research finding that secondhand smoke exposure is a serious cause of disease and death.

The study followed more than 4,700 British men over the course of twenty years and compared the cotinine levels in their blood with their risk for heart disease and stroke. Men with higher cotinine levels demonstrated the 50-60% greater risk of heart disease. Cotinine, which is metabolized nicotine in the blood, is the most reliable measure of secondhand smoke exposure.

This study determined that previous studies that looked only at secondhand smoke exposure in the home from a smoking spouse, rather than including exposure in the workplace, significantly underestimated the risk of heart disease. The study also found that the heart disease risks were especially high for short term exposure to secondhand smoke. This supports the findings of the Helena Heart Study, which found an immediate drop in heart attacks after the city of Helena, MT enacted a smokefree workplace law.

For more information on studies showing the impact of secondhand smoke and smokefree air laws on heart disease, please see the Related Topics box at the top of this page.