The 13th World Conference on Tobacco OR Health

Objective: Assess the full hazards of smoking.

Methods: Smoking became widespread earlier in men, so the first evidence of its full eventual hazards came from studies of men, eg, Richard Doll's study of smoking and death in British doctors (BMJ 2004;328:1519). Valerie Beral's unpublished UK Million Women Study now shows the eventual hazards are similar for women.

Results: For both sexes, mortality in middle age is about three times as great in smokers as in non-smokers. Three main conclusions emerge from the studies of smoking and mortality. First, the hazards are large; about half of all persistent cigarette smokers are eventually killed by their habit. Second, many of these deaths are in middle age (35-69) rather than old age (70+) – about a quarter are killed in middle age by tobacco, losing, on average, over 20 years of non-smoker life expectancy. Third, stopping works remarkably well; even in middle age, stopping before lung cancer or some other fatal disease avoids most of the excess risk of death, and stopping before middle age gains even more. Cessation matters, for about 30 million annually start smoking. If most continue then more than 10 million annually will eventually be killed by it, with a total of about one billion (1000 million) deaths from tobacco this century. A substantial reduction in uptake rates by young adults could prevent hundreds of millions of tobacco deaths in the second half of the century, but only widespread cessation can prevent hundreds of millions in the first half.