Intended for healthcare professionals

Medical Milestones

Risks of smoking: all done and dusted

BMJ 2007; 334 doi: (Published 04 January 2007) Cite this as: BMJ 2007;334:s16
  1. Simon Chapman, professor of public health
  1. 1School of Public Health, Edward Ford Building, University of Sydney, Sydney, NSW 2006, Australia

    Two landmark studies in the 1950s led to a growing body of evidence for the harmful effects of tobacco and a decline in the prevalence of smoking, despite the efforts of the tobacco industry to fight back

    After tobacco was introduced from America to Europe in the 16th century and then to the rest of the world, its detractors lost little time in condemning the practice, which was popularly reputed to benefit health. Early medical reports, including the French physician Nicholas Andry de Boisregard's 1701 warning that people taking too much tobacco could suffer a withering of their “noble parts,” presaged later epidemiology on smoking and erectile dysfunction. In 1771 the Encyclopaedia Britannica recorded “a person who through excess of smoking had dried his brain to that degree, that after his death there was nothing found in his skull but a little black lump, consisting of mere membranes.”

    Serendipitous research

    Fumophobic tracts from luminaries such as Robert Baden-Powell and Henry Ford were imbued with the language of moral turpitude. A generation grew up hearing that smoking might “stunt your growth.” But the real risks of smoking became clear only after a serendipity in 1950: two major case-control studies on smoking's harms were published, one by the Americans Ernst Wynder and Evarts Graham in the Journal of the American Medical Association and the other by the United Kingdom's Richard Doll and Austin Bradford Hill in the British Medical Journal.1 2

    These findings triggered an avalanche of research. Where results were publicised by the media and governments the prevalence of smoking began to fall. Although in the 1950s most countries reported a prevalence of smoking among men of more than 60%, today smokers are typically outnumbered by more than three to one in areas where tobacco control is taken seriously. In California just 9.8% of people smoke daily.

    People smoking 20 cigarettes a day for 40 years will baste their lungs with a toxic, carcinogenic fog 2.9 million times. In compelling them to do this, nicotine has caused unparalleled mortality. Unlike their forebears before 1950, advocates of tobacco control now have the dismal luxury of “great” statistics on which to make their case: worldwide about five million people die each year from tobacco related illness. Among risk factors for disease, only hypertension and malnutrition kill more people than does tobacco.

    In developed countries alone, between 1950 and 2000 smoking caused about 62 million deaths or 13% of all deaths (20% of deaths in men and 4% in women). It has been estimated that tobacco will cause about 150 million deaths worldwide in the first quarter of this century and 300 million in the second quarter.3 In the United States each smoker loses on average 13 years of life.4 The World Health Organization estimates that by 2020 “the burden of disease attributable to tobacco will outweigh that caused by any single disease.”5

    These are numbers to die for. Yet too often the hazards of smoking fail to create a sense of urgency among the media, policy makers, and the public. The statistics are so stratospheric that they have become almost banal. As Stalin said, “A single death is a tragedy; a million deaths are a statistic.” The number of deaths from cancer arising from the 1986 Chernobyl nuclear reactor meltdown is predicted to rise to 16 000 by 2065.6 The International Agency for Research on Cancer stated that “tobacco smoking will cause several thousand times more cancers in the same population.” Few news bulletins picked up on that comparison.

    Tobacco control and falling cancer mortality

    For all the money poured into cancer research in recent decades, most of the progress in reducing cancer mortality has been due to deaths avoided through successful tobacco control. The American Cancer Society recently examined how much the decline in smoking had contributed to the decline in deaths from all cancers in the US. It concluded: “Even our most conservative estimate indicates that reductions in lung cancer, resulting from reductions in tobacco smoking over the last half century, account for about 40% of the decrease in overall male cancer death rates … A more realistic straight line projection of what lung cancer rates might have become suggests that, without reductions in smoking, there would have been virtually no reduction in overall cancer mortality in either men or women since the early 1990s. The payoff from past investments in tobacco control has only just begun.”7

    In the early 1980s, while the tobacco industry was still reeling from growing public awareness of the dangers of active smoking, the second horseman of the industry's apocalypse rode into view: the emerging epidemiological evidence for the harmful effects of secondhand smoke. This broadened the ethical foundations of tobacco control: harming oneself invites paternalistic advice, but harming others justifies laws to protect the community. A Rip van Winkle awaking from a 20 year sleep would be astounded by the cultural transformation of the status of smoking from a pleasant, mannered pastime to a badge of low education, social disadvantage, and ostracism. Cigarette packets have metamorphosed from elegant boxes to pathology museum exhibits.

    At the end of the 1990s the tobacco industry was further undermined by the release under the US Master Settlement Agreement of more than 60 million pages of its internal documents. This effectively halted the industry's longstanding public denials of the dangers to health of smoking, designed to undermine public awareness campaigns.

    Smoking may well continue to be a major health problem in much of the world. However, the world's first legally binding health treaty, the World Health Organization's Framework Convention on Tobacco Control, entered into force in February 2005. Now ratified by 140 nations (but not, notably and disgracefully, by the US), it will unleash unprecedented worldwide controls on the vector for tobacco related disease: the tobacco industry. The force of these events, first set loose by researchers in 1950, means that the end game for smoking may well be just 20 years away in the vanguard of nations where smoking is currently in free fall.


    • Publication of this online supplement is made possible by an educational grant from AstraZeneca

    • Competing interests: SC is editor of Tobacco Control.