The damages of smoking


Millions of people die every year from (active and passive) cigarette smoke. The organs most exposed to the development of pathologies are the respiratory tract, the gastrointestinal tract, the urogenital system and the cardiovascular system. Quitting smoking is possible, albeit difficult. A change in lifestyle and sports are valid tools to fight this scourge.

The damages from smoking can be devastating. In a 2015 study, the World Health Organization estimated that deaths related to direct (active) cigarette smoking are 6 million per year, of which more than 1 million related to lung cancer and the rest to respiratory and cardiovascular diseases. The deaths caused by indirect (passive) smoking, to which children are also exposed, are about 603 thousand a year.

Various factors influence the severity of the damage: the starting age and the number of years of smoking, the quantity of cigarettes consumed daily and the intensity of the inhalations. In any case, the body always suffers the toxic effects of smoking, even when one is not smoking firsthand. We have in fact two categories of subjects affected by smoking. Active smokers inhale it by breathing directly through the cigarette. This smoke is inhaled without dilution, thus giving the smoker high doses of components from the combustion of the cigarette. Passive smokers inhale a mixture from both the smoke that is released from the cigarette that is burning and from that released by the exhalation of the smoker. Both types of smoke combine with air, diluting the harmful compounds. Nonetheless, there are qualitative similarities between the active and passive smoker, which support a generalization of the results regarding the health risks caused by smoking. Recently, the expression “third-hand smoke” has been used to indicate those toxic components of smoke that settle on surfaces and clothes, which persist in interiors and undergo further chemical transformations, also representing a risk for the health.

Cigarette smoke is generated by the combustion, at very high temperatures, of a mix of organic substancestobacco, various additives and paper. This produces an aerosol of approximately 7,000 compounds which include numerous toxic components. Many of these substances are well known: benzene (a leukemogen), formaldehyde (an irritant and carcinogen), benzo(a)pyrene (carcinogen), carbon monoxide and cyanide (asphyxiant), acrolein (an irritant) and polonium (a radioactive carcinogen). In addition, cigarette smoke contains heavy metals and pesticides that accumulate in the body.

Inhaled particles penetrate to the deepest part of the lungs, reaching the bronchioles and pulmonary alveoli. Some substances pass through the lung epithelium and enter the bloodstream where, reaching the heart, they are distributed throughout the body. A part of these compounds is metabolically transformed by the body’s cells into other components, which can be even more dangerous than the initial ones. These transformations depend on the genetics of the individual and define the greater or lesser susceptibility of the subject to tobacco smoke.

The organs most exposed to the development of diseases due to smoking are those belonging to the respiratory tract, as they are directly involved in the aspiration of smoke. Frequent smoke-related diseases in these organs are lung cancer, laryngeal cancer, oral cavity cancer, chronic obstructive pulmonary diseases, pneumonia, acute and chronic bronchitis, asthma. The gastrointestinal tract is also involved both directly, because it shares a part of organs with the respiratory system, and indirectly. Gastrointestinal diseases related to cigarette smoking are esophageal cancer, stomach cancer, gastric ulcer and duodenal ulcer. The urogenital system also suffers the toxic effects of smoking because it is the part of the body responsible for the elimination of inhaled toxic substances through the urine. People exposed to active and passive smoking have an increased risk of bladder, ureter, uterus and kidney cancer and can also develop infertility and impotence. Many pathologies are borne by the cardiovascular system because it is involved in the transmission of toxic substances absorbed at the lung level. The most expressed pathologies in these subjects are myocardial infarction, cerebrovascular diseases, arteriosclerosis.

It is strongly recommended not to smoke during pregnancy as the fetus, having not yet developed defense systems against these harmful substances, is highly exposed to the toxicity of both active and passive smoking. Smoking has a vasoconstrictive effect on the placenta, causing a reduction of nutrients and oxygen to the fetus which could lead to alterations on fetal growth, spontaneous abortion, risk of premature birth and extrauterine pregnancy. Smoking during pregnancy also increases the risk for the fetus to develop mental and behavioral deficits, bronchopulmonary pathologies and tumor pathologies.

Quitting smoking is very difficult as nicotine is highly addictive. On a biochemical level, the most accepted hypothesis is that nicotine dependence is given by the ability of this molecule to stimulate the release of dopamine and serotonin, giving the body the sensation of pleasure and reward. When nicotine levels begin to decrease, neurons induce the feeling of “need” to smoke, to restore neuronal stimulation and therefore a sense of “well-being”. The symptoms of a lack of nicotine (desire to smoke, irritability, depression, nausea, headache and stomach cramps) appear after a few hours (or minutes) from the last cigarette. The smoker then enters the acute phase for the next 3 days, which decreases after 14-21 days from the last cigarette.

Sport can be used to help quit smoking as it stimulates areas of the brain common to those involved in nicotine, giving the same feeling of “well-being” perceived by the smoker after a cigarette. In addition, playing sports causes the production of endorphins, acts as a relief valve to eliminate stress and tension, thus lowering the desire for cigarettes and helping to resist abstinence crises.