The Origin of the Claim that ‘Smoking Kills 50% of Smokers’

Unless Doll copied that idea from someone else, he was the origin. In the final report of The Doctors Study, he repeated that claim several times. (By the way, when I say ‘Doll’, I mean ‘him and his co-authors’. By the time that the final report was written and published, Doll himself was around 80 and probably had little to do with that report. By then, it was probably Peto who was chief author)

The final report was as much propaganda as fact. It isn’t very long, being nine pages. Here is the link:

[Incidentally, there is a statement in there which I hadn’t noticed before. There is a figure for how many doctors were still alive at the end of the study:

“Some 2000 men were already aged 70-89 at the start of the study, and some 4000 of the younger respondents eventually survived to reach their 70th birthday during the fifth decade of the study.”

Doll started with 34,000. If we assume that the above statement about ‘4,000 reaching their 70th birthday’ means ‘were still alive’, that means that 30,000 were no longer with us. But the study only accounted for 25,000 by death, which means that 5,000 had ‘disappeared’. I am glad that I have noticed that because it has confirmed some calculation that I have made in the past]

It is pretty gruesome to read because it is packed with statistics drawn from 50 years of statistics building. I’m pretty sure that Doll was not using a computer when the study started in 1951, but I think that he was by the time of his report after ten years (1961). I don’t know how powerful the computers at that time were. By the time of the final report, we can assume that his computers were able to cope with all sorts of algorithms so that they could spew out whatever correlations that he desired.

This creates a problem for us because of this statement:

“For those born in 1920-1929 the probability of death in middle age (35-69) was 15% in non-smokers and 43% in cigarette smokers, corresponding to a threefold death rate ratio (calculated from the logarithms of the survival probabilities in figure 2 (bottom graph)).”

The mention of using ‘logarithms of survival probabilities’ is troubling (although perfectly legitimate). It paints in my mind a picture of calculations of such complexity that advanced computer models are required to sort them out. That does not surprise me since doctors were dying for all sorts of reasons at all sorts of ages at all sorts of times of year (age standardisation), and some were heavy smokers, some were moderate smokers, some were light smokers and some were non-smokers, and some smoked cigars and some smoked pipes, and many stopped smoking at different times….. etc, etc.


So let’s look where Doll seriously made the first statement about ‘50%’ in that study, even though he had already suggested it. On page 5 (of 9):

For those born in 1900-1909, annual mortality among non-smokers was, both in middle and in old age, about half that among cigarette smokers.”

It’s difficult to pick out what to quote and what not to. For example there is this:

“The results suggest a shift of about 10 years between the overall survival patterns of the continuing
cigarette smokers and the lifelong non-smokers in this particular generation. That is not to say that all such smokers died about 10 years earlier than they would otherwise have done: some were not killed by their habit, but about half were, thereby losing on average more than 10 years of non-smoker life expectancy. Indeed, some of those killed by tobacco must have lost a few decades of life.”

Do you see? The ‘about half’ is scattered all over the place.

The appearance of propaganda becomes more and more prevalent. (page 8):

“This [conscription into the armed forcesestablished in many 18 year olds a persistent habit of smoking substantial numbers of manufactured cigarettes, which could well cause the death of more than half of those who continued.”

And again on page 8:

“…… substantially underestimated the hazards of long term use of tobacco. It now [in the 1990s] seems that about half of all regular cigarette smokers will eventually be killed by their habit. Ten years later, the 50 year findings show that for the continuing cigarette smokers in this study who were born in the first, second, and third decades of the 20th century, the eventual risks vary from about one half to about two thirds, …..”

The next sentence really reveals how much this report has become propaganda:

“It is a new finding that the risk of being killed by tobacco can be as great as two thirds ……” 

Almost all the stats are concerned with smoking cigarettes. We note how this has now become tobacco in general.

Here is that sentence in full:

“It is a new finding that the risk of being killed by tobacco can be as great as two thirds, but this applies directly only to the hazards suffered by this particular group of professional British men during the past half century. If these results are to be used indirectly to help predict the risks that male, female, rich, poor, British, and non-British populations of persistent cigarette smokers are likely to face over the next half century, then it may be more appropriate to retain the previous semi-quantitative conclusion that “smoking kills about one half.”

Do you see where the constant repetition of ‘smoking kills half’ and the desperation of Tobacco Control has come from? Over the next half century. 

This is the final sentence:

The general statement that in many very different populations the future risk of death from persistent cigarette smoking will still be about one half is therefore a reasonable one, and the results thus far in a widening range of studies in other developed and developing country populations such China and India seem consistent with it (as long as the prolonged delay between cause and full effect is properly appreciated). If so, then on current worldwide smoking patterns (whereby about 30% of young adults become smokers) there will be about one billion tobacco deaths in this century, unless there is widespread cessation. For, with low tar cigarettes still involving substantial hazards the quantitative conclusion from this study that seems most likely to be robust is that, even among middle aged smokers, cessation is effective and cessation at earlier ages is even more so.


It is clear, from the words and phrases that the quack professors and doctors (especially Nathanson, who is only ‘Doctor Nathanson’ because the title was conferred on her ‘honoris causa’ (as an ‘honour’) use, that all of the stuff about ‘50%’ was planned long, long ago. The whole propaganda blitz has followed Hitler’s ‘Mein Kamph’ propaganda ideas almost to the letter. “Keep it simple; all shout the same; shout it again and again; never express sympathy for opposing views.


But what about THE FACTS?

Read that final report and look for any suggestion of other factors. There are no such suggestions at all. No other factors for the cause of diseases are permitted. Only smoking causes ‘tobacco related diseases’, but note that ‘tobacco related’ does not mean ‘tobacco specific‘. There are no ‘tobacco specific’ diseases as the McTear Case showed. In that case, it should have been a doddle  for TC to ‘prove merely on the balance of probabilities’ that smoking causes LC. After all, Doll’s Study proved that the ratio of smoker LCs to non-smoker LCs was fifteen to one. Didn’t it? Didn’t it? So why did the WHOLE MEDICAL PROFESSION not dare to produce those ‘facts’ in evidence? I suspect that they did not want their ‘evidence’ to be subjected to intense, legal scrutiny.

It strikes me that Doll et al, and the BMA (which seems to represent ‘health professionals’ these days rather than GPs), set up the ‘evidence’ specifically for political purposes. I do not mean that Doll cheated (although he may have). I mean that the possibility of ‘smoking plus drinking plus smog plus genetic propensity’ was not permitted. We have already seen above how complex the mere consideration of tobacco use, age, cessation, etc, can be. Add also genetics and atmospheric pollution, and even the most sophisticated computer algorithms would struggle.

Shit in, shit out.


One final note.

In that final report, Doll indirectly concedes that, if everyone stopped smoking, the effects of not smoking would only be felt in old age.  He does so in this sentence:

“…..(as long as the prolonged delay between cause and full effect is properly appreciated).”

But the Doctors Study did not show ‘a prolonged delay’ – it showed ‘incidents’, and an accumulation of ‘incidents’. We could equate this, very roughly, with an accumulation of crashes of motor vehicles on a given road. It would be easy to surmise that the reason for the crashes is that the speed limit is too high – therefore the answer is to reduce the speed limit on that road. That reduction might reduce the incidence of crashes, and everyone would applaud. But, what might not have been observed was that the general speed limit was not the problem, since almost all the crashes occurred at a particular place on the road, which just happened to coincide with a severe bend in the road.

To be ‘scientifically’ valid, the study should have shown specific reasons for ‘the prolonged delay’. It did not. Instead, it worked the wrong way round. It went from conclusion to reason for conclusion, and not from reason for conclusion to conclusion.

These sort of things as serious logical errors. It is not necessarily correct to use non-smokers as ‘the norm’. It may be that non-smokers are the exception. We might consider the idea that non-smokers, in the past, were a very odd lot. What was wrong with them? Why did they not smoke when everyone else was smoking? Doll’s Study not only does not answer that question, it does not even ask it.

But it wouldn’t, would it? That is because Doll et al believed in ‘the standard human being’. ‘Standard human beings’ would rather live miserable, deprived, painful lives and die at 80, than live happy, wealthy, pain-free lives and die at 79. That is the logic of The Doctors Study conclusions. Only longevity matters.


11 Responses to “The Origin of the Claim that ‘Smoking Kills 50% of Smokers’”

  1. michaeljmcfadden Says:

    “I’m pretty sure that Doll was not using a computer when the study started in 1951, but I think that he was by the time of his report after ten years (1961).”

    I dunno about that. We often see the claim made that the NASA-type computers used during the 1969 moon landing weren’t much better than 1984’s Commodore 64s with 32k of free RAM. And 1969 would have have been a quantum leap over 1961. And I know that in 1975 there was a “computer geek” trying unsuccessfully to convince the Canadian Peace Research institute to convert its rather intricate (for the time) pin-card filing system (a system using massive index cards with holes punched in their tops that you’d “sort/search” by inserting long metal “knitting needles” through and lifting the right ones up with them) to computer. In 1975 the U of PA was quite proud of its massive “Computer Building” where students could painfully spend hours punching out IBM punch cards, inserting them into a queue, waiting a half hour for the massive central computer to do its thing, and then get back reams of paper that basically said “Error. Job Stopped.” so they could then sit back down and painstakingly try to figure out where they’d mistakenly typed a wrong character or space into their coding. Oh, and that was for a problem like “What does 3 x 5 equal?” Also: in the early 60s the big NY department stores were still operating on a vacuum tube credit system where a cashier would put documents in a little pint-soda-sized cylinder that would get sucked into an octopus of pipes and zoomed up to the 8th floor where accountants would check a customer’s credit-signature against their paper records and zip an “OK!” cylinder back down.

    Computers in 1961 were still pretty primitive and VERY expensive. I’d bet Doll was still dependent on papers/pens/grad-students.

    – MJM

  2. Rose Says:

    I don’t believe that Richard Doll really believed in the standard human being but he may well have massaged them a little to fit, let’s not forget that he missed out the inhaling question on the British Doctors Study after it became inconvenient.

    “But Sir Ronald Fisher, arguably the greatest statistician of the 20th century, had noticed a bizarre anomaly in their results. Doll and Hill had asked their subjects if they inhaled. Fisher showed that men who inhaled were significantly less likely to develop lung cancer than non-inhalers. As Fisher said, “even equality would be a fair knock-out for the theory that smoke in the lung causes cancer.”

    “Doll and Hill decided to follow their preliminary work with a much larger and protracted study. British doctors were asked to take part as subjects. 40.000 volunteered and 20,000 refused. The relative health of smokers, nonsmokers and particularly ex-smokers would be compared over the course of future years. In this trial smokers would no longer be asked whether they inhaled, in spite of the earlier result”
    http: //

    Bear in mind that according to Denial and Delay Richard Doll was a Rockefeller student ( Standard Oil amongst other things) at the time and the study was done in a Rockefeller funded School of Public Health and finding Lung Cancer was caused by air pollution from vehicle exhausts wouldn’t have been a very good start to his career.


    “General Motors, duPont and Standard Oil were making billions of dollars worldwide from selling the lead formula which they had patented while paying for and controlling the research into the health effects for more than 40 years. The research always favoured the industry’s pro-lead views or was suppressed, Mr Kitman found.”
    http: //

    “In 1983 in support of U.S. and U.K petrochemical companies,Doll claimed that lead in petroleum vehicle exhaust was not correlated with increased blood levels and learning disabilities in children.
    Doll’s research had been generously funded by General Motors.”

    Which in fairness Doll had previously denied.
    http: //

    “The London Hospitals study was the first British study to investigate possible causes of the growing epidemic of lung cancer. It was published by Richard Doll and Bradford Hill in 1950.”
    http: //

    After the London Hospital study and the Great London Smog of 1952 –

    “Professor Virginia Berridge of the London School of Hygiene & Tropical Medicine’s History Unit has researched papers relating to cabinet committee meetings in the late ’50s looking into smoking, air pollution and lung cancer”

    “A few years later, in 1957, the Medical Research Council was planning to issue a statement saying although smoking was a significant cause of lung cancer, up to 30% of cases might be caused by air pollution.

    But the Cabinet committee on cancer of the lung, fearful of another political embarrassment which could be caused by stressing the air pollution connection, asked the MRC to reconsider its statement.

    On 31 May 1957 a modified version was published, which asserted that although it was likely that atmospheric pollution did play a role in lung cancer, it was ‘a relatively minor one in comparison with cigarette smoking’.”

    So the statement was deliberately bent to start with to help the government out of a hole.

    Richard Doll seems to have been rather good at this.

    02 Feb 2014
    “No compensation for British servicemen exposed to nuclear explosions around Australia and the Pacific in the 1950s and ’60s”

    Between 1952 and 1962, Britain and the United States caused more than 40 nuclear explosions in the atmosphere around Australia and in the Pacific. Around 21,000 British servicemen were exposed to these explosions, many of whom were dressed in no more than khaki desert fatigues. Approximately 3,000 are thought to be alive today.”
    http: //

    And why?

    A summary of mortality and incidence of cancer in men from the United Kingdom who participated in the United Kingdom’s atmospheric nuclear weapon tests and experimental programmes – 1988

    Richard Doll


    “Most of the differences observed between the participants and controls were interpreted as due to chance, but some may be due to differences in smoking habits.”

    • Rose Says:

      Read that final report and look for any suggestion of other factors. There are no such suggestions at all. No other factors for the cause of diseases are permitted. Only smoking causes ‘tobacco related diseases’

      Injurywatch discovers secret payments for anti-smoking cancer-link Oxford academic Sir Richard Doll by asbestos and chemical industry

      “The Causes of Cancer: Quantitative Estimates of Avoidable Risks of Cancer in the United States Today,”

      “Perversely the 1981 US study which was supposed to cover all environmental and work-related cancers, Doll specifically excluded African Americans and anyone aged over 60 from the statistics when exposure would be expected to be higher among blue collar workers and the poor where African Americans might be deemed to be over-represented because of insurance claims and the locations they live and work in. Similarly the cancer incidence would certainly be expected to be highest in the old.”

      In the interests of balance –

      Leading scientists leap to the defence of ‘corrupt’ Doll- 2006

      “Some of Britain’s most senior scientists have angrily denounced suggestions that Sir Richard Doll, who proved the link between smoking and lung cancer, had deliberately failed to disclose financial dealings with the chemicals industry.

      The scientists said that tens of millions of people owed their lives and health to studies pioneered by Sir Richard. “It is with dismay that we now hear allegations against him that he cannot rebut for himself,” the scientists say in an open letter.”

    • junican Says:

      As regards the ‘inhaling protective effect’, which Fisher noticed, it is worth pointing out that the observation came from the Hospital Study, which preceded the Doctors Study. In the Doctors Study, the question, “Do you inhale?” was dropped.

  3. harleyrider1978 Says:

    Game Point Match…………….tobacco the scapegoat for every ailment!

  4. garyk30 Says:

    “Read that final report and look for any suggestion of other factors. There are no such suggestions at all. No other factors for the cause of diseases are permitted.”

    Dr. J,
    The other factors are there by default.

    Smoking will kill half = 50 out of every 100 smokers deaths

    Thus, the other fifty are, by default, due to other factors.

    Actually, we find that about 50% of smokers deaths from the diseases ’caused’ by smoking are due to other factors.

    Out of 100 smokers deaths
    1. 85 are due to the smoking ’caused’ diseases

    2. 50 are due to smoking(the half)

    3. Thus, 35 of the 85 deaths from the smoking ’caused’ diseases have to be due to other factors.

    4.35 is about, more or less, 50% of 85.

    It is very poor science to say that smoking ’causes’ those diseases when your own data shows that almost 50% of the diseases are due to other factors.

    As for the claim that smokers lose an average of 10 years of life, They don’t mention at what age of death that would happen.
    ‘Life Expectancy at Various Ages”

    At the age of 79, you have an expected average of 10 more years of life.

    Apparently, the average age of death for the smoker doctors was 79 years.

    No mention is made of the average number of expected years of life the never-smokers lost.

  5. garyk30 Says:

    From the final report

    Page 9
    What is already known on this topic:
    About half of all persistent cigarette smokers are killed by
    their habit—a quarter while still in middle age (35-69 years)

    (NOTE: This is the same as saying that half of smokers’ deaths are not due to smoking and 75% of the smokers deaths are over the age of 69 -GK)

    • junican Says:

      I think that there is more to it, which does not involve the maths. What bothers me is transposition of ‘died earlier than’ to ‘killed by’.

  6. J Brown Says:

    The King’s Speech was on telly the other night. At the end of the film it advises that King George VI had been told that smoking would ease his stammer; that he was a chain smoker as a result; that he died at age 56 from lung cancer AS A RESULT of his smoking. Funnily enough, ‘science’ has indicated that stress is a far greater killer than most other causes – here we have a man who is so psychologically stressed that he is unable to communicate properly, yet, that appears to have no bearing in his health or immunity issues. It is just a matter of fact that if you have ever even looked at a cigarette, and succumb to lung cancer (or any other kind of cancer) there are NO other issues involved, other than tobacco. Talk about brainwashing…..these ‘facts’ even infiltrate entertainment film making……

    • junican Says:

      A good observation, J B.
      As usual with these things, there are claims (such as ‘was a chain smoker’) which have to be accepted on trust, and I refuse to accept. He was King, and must have had masses of official engagements where he could not ‘light up’. It must surely be therefore that, if he was a chain smoker, it was only in his private time. We do not know how much ‘private time’ he had.

    • beobrigitte Says:

      Junican, indeed!

      How much ‘private time’ do members of the Royal Family get?

      That does remind me; how many people are currently not able to work due to ‘stress-related’ sickness?

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