1. and the benefits of stopping
The hazards of smoking
and the benefits of stopping
The hazards of smoking
This presentation is about the hazards of smoking
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and the benefits of stopping

2. The hazards of smoking and the benefits of stopping
• This presentation provides evidence from the UK and the USA, where the health effects of smoking have been studied over a long period, but these findings apply to many other countries
Particular emphasis is given to the risk of death in middle age (defined as ages 35-69)
Available on
The hazards of smoking and the benefits of stopping
This presentation provides evidence from the UK and the USA, where the health effects of smoking have been studied over a long period, but these findings apply to many other countries.
The first big studies of smoking were done in the United Kingdom and the United States of America, but their findings apply to many other countries. The risks for persistent cigarette smokers (those who start in early adult life and never stop) are likely to be much the same everywhere.
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Particular emphasis is given to the risk of death in middle age (defined as ages 35-69)
Available on
The website also provides presentations on the total numbers of deaths from smoking in each of forty countries and five groupings of countries (such as the European Union, or All “developed” countries), but this presentation is mainly about the risks of smoking for the individual.

3. Main messages for the individual smoker
• The risk is big: about half are killed
Those killed in middle age lose many years
Stopping smoking works
Even in early middle age, those who stop (before they have lung cancer or some other fatal disease) avoid most of their risk of being killed by tobacco
Stopping before middle age works even better
Main messages for the individual smoker
The risk is big: about half are killed
There are three main messages for the individual smoker. First, the risk of death from smoking is big. The reason smoking matters is not just because it’s dangerous, but because it’s so dangerous; about half of all persistent cigarette smokers are eventually killed by their habit.
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Those killed in middle age lose many years
Second, many are killed while they are still only in middle age (which, throughout, means years of age), and many of those killed in middle age could have lived on for another 10, 20, 30 or more good years.
Stopping smoking works
And, finally, stopping smoking works. Both for those who already smoke, and for those who will start to smoke in the future, what matters is not only the hazards of smoking but also the benefits of stopping.
- Even in early middle age (for example, at around age 40) those who stop (before they have lung cancer or some other fatal disease) avoid most of their risk of being killed by tobacco
- (And, of course …) Stopping before middle age works even better

4. Stopping smoking: avoiding lung cancer
Continued smoking: % dead from lung cancer 15 10 5
% dead from lung cancer
Stopped age 50: 6%
Stopping smoking: avoiding lung cancer
This graph shows how small the risk of dying of lung cancer is for people who never smoke – it’s less than 1%.
It also shows how big the risk of lung cancer is for people who continue to smoke.
16% will die from lung cancer by age 75, if they don’t die from something else first (and, smoking causes even more deaths from other diseases than from lung cancer; overall, half of all persistent smokers are killed by tobacco).
For people who stop at age 50, the risk of dying of lung cancer is about 6%, which is a lot bigger than the non-smoker’s risk, but the key point is that it’s a lot smaller than the smoker’s risk.
If you are a 50-year-old smoker who doesn’t yet have lung cancer, you don’t any longer have the option of being a never-smoker; your choice is between stopping at age 50, or continuing, and this graph shows that stopping still makes a big difference to your lung cancer risk.
Finally, stopping at age 30 is much better than stopping at age 50, and it’s very much better than continuing.
Cumulative risk at UK male 1990 rates BMJ 2000; 321: 323-9
Stopped age 30: 2%
Never smoked: <1% 45 55 65 75
Age

5. Delay between cause and effect: cigarettes, then lung cancer deaths
cigarette consumption +
Lung cancer deaths per million per year
500
1,000 10 5
Cigarettes per adult per day
lung cancer
Delay between cause and effect: cigarettes, then lung cancer deaths
When there is a big increase in cigarette smoking among the young adults in a particular country, the main increase in deaths from smoking comes decades later, when those cigarette smokers reach middle age. For example, here’s what happened over the past hundred years to cigarette smoking in the US.
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This shows the average number of cigarettes consumed per US adult per day from 1900 to the year This consumption is averaged over all US adults, not just the smokers. Cigarette smoking became common first among men and then, decades later, among women. In recent years there’s been a decrease; Americans now smoke only half as many cigarettes as they did.
And here’s what happened to lung cancer deaths, first among American men and then among American women.
Eventually, after a delay of a few decades, there was a huge increase in male lung cancer deaths, but over the next few decades there will be a substantial decrease because so many smokers have already stopped.
Finally, here are the female lung cancer deaths. Both in men and in women lung cancer now causes more deaths than any other type of cancer.
The American experience illustrates the fact that if the adults in any country smoke an average of about ten cigarettes a day (for example, if half smoked nothing and half smoked 20 a day) then after a delay of some decades this will eventually cause massive death rates.
Of course, lung cancer is not the only disease caused by smoking. Information on the overall hazards of smoking came from a big survey that began in the 1950s in the UK, where the lung cancer epidemic had started even earlier than in America.
lung cancer
1900
1920
1940
1960
1980
2000
USA:

6. Long-term study of persistent smoking
• UK men born in the 20th century: first population in the world exposed to really prolonged cigarette smoking
They were studied for 50 years by Richard Doll
Source: “Mortality in relation to smoking: 50 years’ observations on male British doctors” Doll R, Peto R et al. BMJ 2004; 328:
Long-term study of persistent smoking
The longest-running study of smoking and death was done in the UK. Its early results showed that smoking could cause many different diseases, and its final results (after 50 years) showed for the first time the full life-long risks of smoking. This is because …
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UK men born in the 20th century were the first population in the world to be exposed to really prolonged cigarette smoking
They were studied for 50 years by Richard Doll
Source: “Mortality in relation to smoking: 50 years’ observations on male British doctors”. Doll R, Peto R et al. BMJ 2004; 328:
The results were published in the British Medical Journal.

7. Study of smoking and death in male British doctors
• Asked all UK doctors in 1951, and periodically thereafter, what they themselves smoked
Recorded all deaths for 50 years ( )
Main findings (for men born in the 20th century)
Smokers lose, on average, 10 years of healthy life
Stopping smoking works
Study of smoking and death in male British doctors
(Richard Doll) asked all UK doctors in 1951, and periodically thereafter, what they themselves smoked
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(He then) recorded all deaths for 50 years ( )
(Here are his) main findings (for men born in the 20th century):
- (He showed that) smokers lose, on average, 10 years of healthy life
- (Second, he showed very clearly that) stopping smoking works
The next two slides show in more detail his main findings about death in middle age, and death in old age. First, the effects of smoking…

8. Survival to age 70 and beyond: effect of smoking in male British doctors20 40 60 80
100 97 94 91 81 59 26 24 4 2
Non-smokers
81%
10 years
58%
% survival from age 35
10 years
Cigarette smokers
Survival to age 70 and beyond: effect of smoking in male British doctors
Here are Richard Doll’s main findings for smoking and death in British doctors.
This graph shows the chances of a 35-year-old surviving to age 70 and beyond. 
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Here are the non-smokers. 81% were still alive at age 70; that means that only 19% had died in middle age.
Now here are the cigarette smokers. Only 58% were still alive at 70; that means 42% had died in middle age.
This difference of 23% (between 81% survival in the non-smokers and 58% survival in the smokers) arose because about a quarter of all the smokers had been killed by tobacco when they were still in middle age (35-69), mainly from diseases such as lung cancer, heart attack and chronic lung disease.
Of course, everybody will die sooner or later: it’s just that, on average, the smokers died 10 years sooner. 81% of the smokers were alive at 60, while 81% of the non-smokers were still alive at 70.
Likewise, 58% of the smokers were alive at 70, while 59% of the non-smokers were still alive at 80.
Of course this 10-year shift is just the average. Some smokers are not killed by tobacco, while many others lose 10, 20, 30 or more good years.
And, next, the effects of stopping smoking… 40 50 60 70 80 90
100
Age

9. Effect of stopping smoking at about age 40
% survival from age 40 20 40 60 80
100
Cigarette smokers
Ex-smokers stopped at 35-44
and gained about 9 years
Effect of stopping smoking at about age 40
The other main finding from Richard Doll’s study was that stopping smoking worked remarkably well.
Even in early middle age (for example, about age 40) , those who stopped before they had incurable lung cancer or some other fatal disease avoided most of their risk of being killed by tobacco, and stopping before middle age was even better.
These are the results for those who stopped at about 40 years of age.
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Here are the non-smokers …
And here are the smokers, losing about 10 years on average …
And here are the people who stopped smoking at about age 40.
Instead of losing 10 years, they lost only about 1 year.
So, by stopping at 40 they gained about 9 years of life, on average.
Partly because of this study many smokers stopped, and the UK death rates from smoking decreased sharply.
Non-smokers 40 50 60 70 80 90
100
Age

10. Decrease in smoking prevalence
United Kingdom,
Decrease in smoking prevalence
% smoked
In 1950, about 80% of UK men smoked 20 40 60 80
70%
In 1970, UK male death rates from smoking were the worst in the world
, decrease in male death rates from smoking was the best in the world
% at ages 35-59
50%
% smoked
Decrease in UK smoking prevalence (at ages 35-59)
Back in 1950, about 80% of all the men in the UK smoked tobacco.
(This was true not just in middle age, but also in older and younger men. Few older women smoked, but many younger women did so.)
During the 1950s and 1960s the medical evidence about smoking strengthened, and efforts got under way to persuade people to stop. All this time, the UK death rates from smoking were still rising.
In 1970, UK male death rates from smoking were the worst in the world
Tobacco control became more effective around the 1970s in the UK, and
(Over the period) , the decrease in male death rates from smoking was the best in the world
The sharpest decrease was among middle-aged men, and the next slide describes the situation back in 1970 for middle-aged men in the UK….
28%
26%
1950
1960
1970
1980
1990
2000

11. Looking back to 1970 death rates: of 100 men aged 35 …
United Kingdom, 1970
Looking back to 1970 death rates: of 100 men aged 35 …
*risks at year 1970 death rates for ages 35-69
• 42 would have died in middle age*
42%
• 20 of these 42 deaths would have been from smoking 20
Looking back to 1970 death rates: of 100 men aged 35 …
[A grey bar appears to indicate 100 men aged 35 years]
What would have been expected to happen among 100 men aged 35?
How many would have died in middle age? (that is, at ages 35-69)
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42 would have died in middle age
Overall, 42 would have died in middle age (that is, there would have been a 42% risk of dying in middle age)
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20 of these 42 deaths would have been from smoking 
And, 20 of these 42 deaths would have been from smoking. That is a calculation for the UK as a whole, including both smokers and non-smokers. The risks just among the smokers were, of course, even greater.
These were the risks of death in middle age at 1970 death rates. What would these same risks have been at the UK death rates of earlier and of later decades?

12. Male death in middle age: changing hazards*
United Kingdom,
Male death in middle age: changing hazards* 15 18 19 20 17 16 14 11 8 6
Smoking
44%
43%
42%
39%
37%
35%
31%
28%
25%
All causes
*risks at period-specific death rates for ages 35-69
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
United Kingdom,
Male death in middle age: changing hazards
[Grey bars appear to indicate 100 men aged 35 years for 1950, 1955 … 2000]
Consider what would have happened to 100 men aged 35, at the death rates of previous decades
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Here we have the overall probabilities of death in middle age from any cause. The overall death rates in UK men stayed about the same from 1950 to 1970, but then suddenly things started to get much better. At year 2000 death rates, only 25% would die in middle age. This is a big improvement since 1970, and it’s still continuing. In each period, how much of the risk was caused by smoking?
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This much! Deaths in middle age from smoking were still increasing until 1965 in the UK, as a delayed result of the increases in cigarette smoking in the first half of the century. Then, deaths from smoking suddenly started to fall, chiefly because lots of smokers stopped. (Other things helped, like life-saving treatments for heart attacks, and changes in the type of cigarette – but, even low-tar cigarettes can eventually kill about half of those who keep on smoking them.)
Most of the big decrease from 42% down to 25% in UK male death rates since 1970 has been caused by the big decrease in death rates from smoking (from 20% down to 6%). Still, however, smoking is causing about a quarter of all the UK male deaths in middle age, but it used to be causing almost half of them.
Cigarette smoking could produce risks as bad as this in any other population; if people in other countries smoke like the British did, they will die from smoking like the British did. And, if they stop, they will avoid those risks. For example, consider Poland, where the big increase in cigarette smoking was around the middle of the last century.

13. Male death in middle age: changing hazards*
Poland,
Male death in middle age: changing hazards* 6 8 9 12 13 16 19 20
Smoking
44%
All causes
40%
39%
41%
46%
47%
45%
*risks at period-specific death rates for ages 35-69
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
Poland,
Male death in middle age: changing hazards
[Grey bars appear to indicate 100 men aged 35 years for 1955, 1960 … 2000]
Again, consider what would have happened to 100 men aged 35, at the Polish death rates of previous decades…
[CLICK] [White bars appear with a percentage in black on each one]
Here we have the overall probabilities of death in middle age from any cause.
[CLICK] [Orange bars appear with a number in white on each one]
And here’s how much of the risk was caused by smoking.
Because the big increase in cigarette smoking came later in Poland than in Britain, the big increase in tobacco deaths also came later.
Poland in 1990 was like Britain in 1970.
Then, during the 1990s, many Polish smokers stopped smoking, and Polish death rates from smoking started to fall.
(There were also other changes in Poland, which helped make death from heart attack less likely, but smoking cessation during the 1990s was important.)

14. Main messages for the individual smoker
• The risk is big: about half are killed
Those killed in middle age may well lose 10, 20, 30 or more good years
Stopping smoking works
Main messages for the individual smoker
National patterns of smoking, and of death from smoking, have been very different in different countries, but for the individual cigarette smoker in any country the overall risks are probably much the same; if they start to be habitual cigarette smokers in adolescence or early adult life, and do not stop, then about half will eventually be killed by it.
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The risk is big: about half are killed
To re-cap, there are three main messages for the individual smoker. First, the risk of death due to smoking is big: about half of all persistent cigarette smokers are eventually killed by their habit.
Those killed in middle age may well lose 10, 20, 30 or more good years
Second, many are killed while still only in middle age, and many of those killed in middle age could have lived on for another 10, 20, 30 or more good years.
Stopping smoking works
And, finally, stopping smoking works remarkably well. For the population as a whole, a big decrease over the next decade or two in the number who start smoking will produce a big decrease in deaths around the middle and the second half of the present century. A big decrease in tobacco deaths in the first half of the 21st century, however, requires many current smokers to stop.

15. Finally, here’s a nice example of what stopping smoking can offer.
This is Richard Doll, who stopped smoking cigarettes in 1949, at age 37, looking happy in 2004, at age 91, as he presented his 50-year results to a press conference.
He may well have saved his own life, and he certainly saved many other people’s lives.
Richard Doll ( ), who stopped smoking cigarettes at age 37, photographed aged 91 at the 2004 BMJ press conference on the 50-year results from his study of British doctors
Michael Crabtree, copyright Troika Photos

16. Deaths from smoking: an electronic resource
Published by International Union Against Cancer (UICC), Geneva: Switzerland, 2006
Funded by
Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), University of Oxford
International Union Against Cancer (UICC)
Fogarty International Center, US NIH
UK Medical Research Council
Cancer Research UK
Project team Richard Peto, Judith Watt, Jillian Boreham
Project management Sinéad Jones
Advice and support Steve Woodward, Konrad Jamrozik, Lesley Walker, Trish Cotter
Design bwa-design.co.uk
And, finally, a reminder that this presentation and more material is available on this website.