Along with the pleasures of smoking there are real risks of serious diseases such as lung cancer, respiratory disease and heart disease, and for many people, smoking is difficult to quit.
Smoking is a cause of various serious and fatal diseases, including lung cancer, emphysema, chronic bronchitis and heart diseases.
The health risks of smoking are derived from epidemiology. Epidemiology is a statistically based science, dealing with risks among large groups of people, rather than with individuals. Through questionnaires and observations of people, epidemiological studies can identify the incidence of disease in a given group, such as smokers, and compare it with the incidence in another group, such as non-smokers.
Over many years, epidemiological studies have consistently reported a much higher incidence of certain diseases among smokers compared with non-smokers. The studies also report that the risks are reduced after quitting and that quitting earlier has by far the best effect on reducing risks.
Traditionally, epidemiology has been used to identify associations that point to possible causes of a disease, providing direction for thorough laboratory investigations. With smoking, the many laboratory investigations over the years have proved more problematic, and science has not to date been able to identify biological mechanisms which can explain with certainty the statistical findings linking smoking and certain diseases, nor has science to date been able to clarify the role of particular smoke constituents in these disease processes.
This means that science is still to determine which smokers will get a smoking related disease and which will not. Nor can science tell whether any individual became ill solely because they smoked. This is, in part, because all the diseases that have been associated with smoking also occur in life-long non-smokers.
We do not point out these scientific limitations to cast doubt that smoking is a cause of serious disease. An important point is that the lack of complete understanding about the biological aspects of the disease mechanisms, and the role of particular smoke constituents, creates uncertainty for efforts to design less harmful cigarettes. Our own work for many years has included, and still includes, research into the assessment of potentially less harmful cigarettes. We remain committed to this work, although the scientific uncertainties make it a major challenge.
For more about our research efforts see Harm reduction, Is there a less harmful cigarette? and Research & Development.
What people should consider about the risks:
- Smoking is a cause of various serious and fatal diseases.
- The health risks in groups vary by the amount smoked, being highest in those that smoke for more years and smoke more cigarettes per day.
- The risks reduce in groups of people who quit smoking, and the reductions increase from quitting earlier.
- Experts advise no smoking during pregnancy.
- The only way to be certain of avoiding the risks of smoking is not to smoke.