Tobacco smoking is projected to cause one billion deaths worldwide this century, mainly in low- and middle-income countries (LMICs) such as China. Two thirds of adult men in China smoke; the study, led by researchers from Nuffield Department of Population Health, UK, Peking University and the Chinese Academy of Medical Sciences shows that around half of those who start smoking cigarettes as young men (before the age of 18) will eventually be killed by tobacco, unless they give up permanently. Smoking also increases the risks of developing a wide range of conditions that do not generally cause deaths, such as asthma, peptic ulcer, cataract, diabetes, and other metabolic diseases.
The adverse effects of smoking have been known for many years, but very few studies, even those in high-income Western countries, have systematically assessed the impact of smoking on an extensive range of diseases within the same population. The researchers used data from the China Kadoorie Biobank to comprehensively assess the health effects of tobacco smoking on death and hospitalisation from a range of diseases and to examine the benefit of smoking cessation.
The study included over 512,000 adults who were recruited during 2004-08 from 10 diverse urban and rural areas across China. They were interviewed about lifestyle and behavior factors, including detailed smoking information, such as the ages at which they started smoking and the type of tobacco products they used. Their answers were validated objectively using exhaled carbon monoxide.