Named non-obvious danger of smoking: harm not only lungs n

A recent study published in the journal BMJ Open revealed serious gaps in smokers' awareness of these risks. More than 9 in 10 people surveyed in 46 countries knew that smoking caused lung cancer, but far fewer people knew about its effects on the cardiovascular system. Even fewer people knew that secondhand smoke was dangerous to the cardiovascular system, CNN reported.

About why smoking so much affects the heart and blood vessels, and how dangerous passive smoking, says CNN expert on healthy lifestyle Dr. Liana Wen, an ambulance doctor and assistant professor of clinical medicine at George Washington University.

As part of the study, the researchers analyzed data from two large international surveys on smoking. One is the International Tobacco Control Project, which surveyed 26 countries between 2002 and 2022. The second is the Global Survey of Adult Tobacco Use, which surveyed 32 countries between 2008 and 2020. Participants in the survey, smokers over the age of 18, were asked if they knew or believed that smoking caused lung cancer, heart disease, heart attack and stroke. They were also asked if secondhand smoke causes lung cancer, heart disease and heart attack in non-smokers.

The researchers analyzed data from the two surveys separately, and the results matched. About 92% of smokers knew that smoking could cause lung cancer. For comparison, 85% of participants in one survey knew about the relationship of smoking with heart disease, and 80% of participants in another survey knew about the relationship of smoking with heart attack. Only 75% and 66%, respectively, knew that smoking was associated with stroke.

For passive smoking, the gap was even greater. Depending on the survey, between 77% and 82% of respondents knew that secondhand smoke caused lung cancer, and only 62% to 73% knew that it caused cardiovascular disease or heart attack.

Another notable finding, emphasizes Dr. Liana Wen, was that over the entire time of observation, progress was generally insignificant. For the five aspects of the health effects of smoking studied, the average increase in awareness was just 0.14 percentage points per year.

Smoking is one of the leading preventable causes of cardiovascular disease, Dr. Wen continues. In fact, according to researchers, around 2.6 million people died worldwide from smoking-related cardiovascular disease and stroke in 2019. This is twice as many as 1.3 million deaths from lung, trachea and bronchi cancers linked to smoking. Anyone who believes that the main danger of smoking is lung cancer does not see the whole picture.

Knowledge influences behavior, says Liana Wen. Someone who understands the risks may be more motivated to quit smoking. This also applies to passive smoking. If smokers do not realize that their smoke increases the risk of cardiovascular disease in others, they may not take action to protect family members, friends and colleagues from exposure to tobacco smoke.

Cigarette smoke contains thousands of chemicals, many of which damage the cardiovascular system, damaging the inner lining of blood vessels and causing inflammation. These toxins also contribute to the formation of plaques inside arteries. In addition, smoking increases the likelihood of blood clotting. A heart attack usually occurs when a blood clot blocks blood flow to the artery that feeds the heart. An ischemic stroke occurs when blood flow to part of the brain is blocked.

Smoking also affects the cardiovascular system, Dr. Wen points out. Nicotine increases heart rate and blood pressure. Carbon monoxide released during combustion reduces the amount of oxygen that blood can carry. Over time, smoking can narrow blood vessels and lead to the development of cardiovascular disease.

These effects are not only seen in people who have smoked heavily for decades. Damage to the cardiovascular system begins early, and relatively low levels of cigarette smoking can carry significant risk.

People exposed to secondhand smoke inhale many of the same toxic chemicals as a smoker. These chemicals can cause similar damage to blood vessels, increase inflammation and thus increase the risk of coronary heart disease.

In this case, the impact on public health is also significant. The study estimates that secondhand smoke caused an estimated 1.3 million deaths worldwide in 2021 among non-smokers. However, in several high-income countries, including the United States, Canada, England, Australia and Germany, less than half were aware of the risk.

The link between smoking and lung cancer has been central to public health reports for decades. This link appears in education campaigns and warnings about the dangers of tobacco and is rightly firmly rooted in the public consciousness. Consequences for the cardiovascular system have not received the same recognition, emphasizes Liana Wen. This study identified significant differences between countries that may reflect differences in media campaigns and other educational activities.

Asked by CNN whether cutting down on cigarettes actually significantly reduces the risk of heart disease or whether someone needs to quit completely, Dr. Wen said, “Reducing consumption is not the same as quitting smoking.” There is a common misconception that the risk of cardiovascular disease in a person who smokes only a few cigarettes a day is several times lower than in a person who smokes a pack of cigarettes a day. That's not true. Even low levels of cigarette smoking significantly increase the risk of cardiovascular disease.”.

The goal, she said, should be to quit smoking altogether. The good news is that the positive effects on the cardiovascular system begin to appear immediately after quitting smoking. The heart rate and blood pressure decrease, the level of carbon monoxide in the blood decreases, and over time the risk of heart attack, stroke and other diseases associated with smoking is significantly reduced.

In any case, you can not think that the harm has already been done and there is no point in quitting smoking right now, the expert warns. Quitting smoking is helpful at any age, and the sooner you do, the more health benefits you’ll get.