Ask most smokers whether cigarettes can cause cancer, and they’ll say yes. That connection has been drummed into public consciousness for decades – on warning labels, in health campaigns, in physician waiting rooms. But ask those same smokers whether cigarettes can trigger a heart attack or stroke, and the awareness drops, sometimes sharply.
New research suggests that while many smokers understand the cancer risk, a major part of the danger remains less visible: the damage smoking can do to the heart and brain.
A study published in the journal BMJ Open found that awareness of smoking’s cardiovascular risks, including heart disease, heart attack, and stroke, remains significantly lower than awareness of its link to lung cancer.
Their findings highlight a troubling disconnect between the health consequences smokers recognize most and the ones that contribute to a large share of tobacco-related deaths worldwide.
What Researchers Found After Surveying Smokers in 46 Countries
The study drew on two of the largest international tobacco surveillance programs ever conducted, and the findings held in both directions.
CNN reported on the analysis in a Q&A with Dr. Leana Wen, a CNN wellness expert and clinical associate professor at George Washington University.
The analysis examined data from the International Tobacco Control Project, which followed adult smokers in 26 countries from 2002 to 2022, and the Global Adult Tobacco Survey, which covered 32 countries from 2008 to 2020. Because several countries appeared in both datasets, the combined research included information from 46 nations.
Both surveys asked smokers whether they understood the connection between cigarettes and several serious health conditions. Lung cancer remained the most recognized risk, with about 92 percent of respondents identifying the link.
Awareness of cardiovascular risks was lower. In one analysis, 85% of smokers connected smoking with heart disease, while another found that 80% recognized the link to heart attack. Stroke was the least recognized danger, with awareness ranging from 66% to 75%, depending on the survey. That means more than one in three smokers did not identify cigarettes as a stroke risk.
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The Risk Fewer Smokers Recognize Is Linked to More Deaths
There is a striking mismatch between what smokers are most afraid of and where the global mortality burden from tobacco actually falls.
The study authors cited figures showing that smoking-related heart disease and stroke together caused approximately 2.6 million deaths worldwide in 2019. By comparison, cancers of the lung, trachea and bronchus accounted for roughly 1.3 million deaths. Based on those estimates, cardiovascular disease linked to smoking caused about twice as many deaths as those cancers.
Dr. Leana Wen said part of the problem may come from decades of public health messaging. The connection between cigarettes and lung cancer has been repeatedly emphasized, while the cardiovascular effects have not received the same level of attention. As a result, some smokers may focus heavily on cancer risk while overlooking another major threat.
The researchers also found that awareness has changed very little over time. Across the five health effects measured in the analysis, recognition increased by an average of only 0.14 percentage points per year. After two decades of tobacco education efforts, the knowledge gap remained largely intact.
What Cigarette Smoke Does to the Heart and Brain
The mechanism behind smoking-related heart attacks and strokes is well understood. It starts long before symptoms appear.
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Cigarette smoke contains thousands of chemicals that can harm blood vessels. This damage contributes to inflammation and encourages plaque buildup inside arteries. Smoking also increases the likelihood of blood clots, while nicotine raises heart rate and blood pressure.
Over time, these effects can narrow and stiffen blood vessels, increasing the risk of cardiovascular disease throughout the body.
A heart attack occurs when a clot blocks blood flow to the heart. A stroke occurs when a similar interruption affects the brain. Dr. Wen told CNN that these outcomes are not limited to people who have smoked heavily for many years. Cardiovascular damage can begin earlier, and even lower levels of smoking can still carry significant risk.
That is an important distinction for people who view occasional smoking as relatively harmless. Smoking fewer cigarettes may reduce exposure, but it does not remove the cardiovascular danger.
The Danger Does Not Stop With the Smoker
People who have never touched a cigarette can still absorb cardiovascular risk from tobacco smoke, and most don’t realize it.
Secondhand smoke exposes nonsmokers to many of the same toxic chemicals inhaled by smokers. That exposure can damage blood vessels, increase inflammation, and raise the risk of coronary heart disease. It is also linked to heart attack, stroke, and other cardiovascular conditions.
Dr. Wen said smoking in another room or opening a window does not remove exposure completely.
She advised keeping smoke away from children, pregnant people, and individuals with existing cardiovascular or respiratory conditions.
The Benefits of Quitting Begin Sooner Than Most People Expect
Complete cessation is the goal, and the body begins responding in measurable ways well before the first year is out.
Dr. Wen emphasized that quitting completely, rather than only cutting down, provides the greatest benefit. She also noted that unsuccessful quit attempts can still provide useful information by revealing triggers and showing what support may be needed in the future.
Nicotine-replacement therapy, prescription medication, and behavioral counseling are established quitting tools. Combining medication-based support with counseling can improve the chances of success, and formal stop-smoking services can provide additional guidance.
The health improvements begin sooner than many people expect. According to the British Heart Foundation, heart rate and blood pressure start moving back toward normal within 20 minutes after the last cigarette. After one year without smoking, a former smoker’s heart-attack risk drops to half that of someone who continues smoking.
For people who have smoked for years, quitting can still make a meaningful difference. The earlier someone stops, the more time they have to gain those benefits, but improvements begin as soon as smoking ends.
Has lung cancer always been the smoking risk you thought about most, or has the cardiovascular connection ever factored into how you or someone you know has weighed the decision to quit?
