Tobacco and Health: Towards a Contemporary Perspective

There is not one tobacco hazard, there are many. Already in the eighteenth century, pipe smoking was linked to cancer of the lip. Cancer of the mouth and throat was added to that list in the nineteenth century.¹ By 1946, medical scholars found that lung cancer cases had tripled in the last three decades.² Lung cancer had been very rare in the early years of the twentieth century. Scientific literature on the subject was scarce. When the number of instances of lung cancers had augmented, medical scholars debated on various possible causes. In 1923, the German Society for Pathology identified several probable causes for the rising number of lung cancers, including asphalt dust and tar emissions from newly paved roads, exposure to chemical warfare in the World War I, air pollution, the growing popularity of cigarettes, increased exposure to X-rays, and even interracial marriages.³ In the 1940s, American researchers on cancer argued whether the steep rise in the instances of lung cancer was not simply “an artefact of new technical abilities to clearly diagnose diseases previously invisible to both medical science and public health?”⁴ A British epidemiologist, Richard Doll, who reflected in an interview taken in 1991 on his work from 1948 on lung cancer, explained that it was not logical to link the rise of instances of lung cancer to smoking as “[c]igarette smoking was such a normal thing and had been for such a long time that it was difficult to think that it could be associated with any disease.”⁵ At the time, Doll would have “put his money” on the tarring of roads or the exhausts of motor cars, to explain the rising instances of lung cancer after World War II. This anecdote by Doll is an example of how the cigarette had already been institutionalized in daily life by the middle of the twentieth century. The unquestioned use of cigarettes made the product an unlikely suspect to account for a rising number of lung cancer diagnoses.

Nonetheless, there were some dissident voices. American newspapers reported several times during the first decades of the twentieth century on young men being destroyed by the poisonous effects of nicotine or the carbon monoxides of cigarette smoke.⁶ Many physicians and surgeons warned about the negative physical and mental effects of smoking cigarettes.⁷ Even when combined with moral arguments on the degenerate consequences of smoking, the anti-tobacco movement faced a seemingly insurmountable task. Consumption of the cigarette rose thanks to the industry’s mass-marketing techniques and nicotine’s addictiveness. “The very popularity of the cigarette typically was cited as medical reassurance. How could the cigarette be dangerous if so many millions of Americans used it regularly without any apparent consequences?”⁸

Hermann Rottmann, a German physician, who researched the causal link between lung cancer and smoking, is generally credited with being the first scientist to have linked lung cancer with tobacco use. Though not correct in his explanation, Rottmann observed that women working in tobacco factories were more likely to get lung cancer. He thought the tobacco dust caused the cancer. The simple truth is that these workers had easy access to cigarettes and therefore became chain-smokers. This led to higher disease rates.⁹ In the 1930s, statistical research on both sides of the Atlantic showed that patients with lung cancer were very often smokers. Although Brandt remarks that: “[i]t was one thing to suggest that smoking might harm susceptible individuals, and quite another to claim that it caused serious disease.”¹⁰ Studies were afraid to answer the causation question with “yes” or “no”. Much was still uncertain. Individual variation seemed to have great influence. The elusiveness of this causal link prompted questions on some of the deepest issues in science. “How do we know?”, “[a]re there alternate ways of knowing?” and “[w]hat constitutes proof?”¹¹

A German physician and researcher, named Robert Koch, established a set of postulates to identify causal organisms in 1884. Koch singled out four postulates to serve as a fundamental basis to determine causality in instances of infection. His four postulates to determine such an organism were that it could be: (1) identified, (2) isolated, (3) grown in culture, and (4) utilized to induce disease. This model was met with negative criticism from physicians, including Koch himself. Although he himself was diagnosed as being infected with the tubercle bacillus, he showed no signs of the disease of Tuberculosis whatsoever.¹² By the 1950s, medical science understood that chronic diseases had to be explained through multicausal schemes. The value of Koch’s postulates lies in the fact that it made other, more abstract approaches to causality seem outdated. In addition, it opened the door for more modern forms of epidemiological methods.¹³

Doering and Lombard, two pioneering American epidemiologists, concluded in an article, which was published in 1928 in The New England Journal of Medicine, that “heavy smoking had some relation to cancer in general.”¹⁴ Frederick Hoffman, a statistician who analysed smoking as a cause of cancer, brought out a report in 1931. He described difficulties in testing these links and attributed them to test-subjects who had only recently switched to cigarettes as a preferred form of tobacco consumption. Smokers also had difficulty with remembering the amounts of cigarettes they smoked.

These methodological difficulties did not hold Hoffman from concluding that he was “strongly inclined to think that the increase [in lung cancer] is directly connected with the much wider spread of cigarette smoking habits.” One of these habits, according to Hoffman, included the inhaling of the smoke into the lungs.¹⁵ Hoffmann remained fairly mild in his advice to smokers. He urged smokers to smoke with moderation.¹⁶ During the 1930s, the relationship between smoking and health hazards was an unresolved medical debate and it would remain so for another two decades.¹⁷ Obstacles concerning methodology in epidemiology would remain problematic to assess the link between smoking and cancer in a conclusive manner until the late 1940s.¹⁸

In the 1930s and 1940s, Proctor argues, three important sources of evidence were established to link smoking to lung cancer. (1) The first is epidemiology, where cancer rates among smokers and non-smokers were compared.¹⁹ These epidemiological studies further allowed patients to be ordered according to age, sex, occupation, and so forth. Studies could be styled in both a prospective and retrospective manner. The results of these studies linked smokers to lung cancer. One study by the English epidemiologists Doll and Hill arrived at a p value of 0.00000064. In other words the statistical significance (p), or the possibility that the relationship between smoking and lung cancer was merely coincidental, was less than one in a million.²⁰ American colleagues of Doll and Hill came to the same conclusion.²¹ (2) A second method involved animal experiments. In these “mouse painting” experiments, backs of mice were shaved and smeared with tobacco tars. These mice soon developed tumours.²² These findings gave strong support to the epidemiological studies of Doll and Hill.²³ (3) A third line of survey comprised studies in cellular pathology. During autopsy, doctors found that precancerous changes in lung tissues were directly associated with exposure to tobacco smoke. By the mid-1950s, these three complementary sources of evidence -epidemiology, animal experiments, and pathologic evidence- had shown a clear and strong association between lung cancer and individual tobacco use.²⁴

Still, many researchers were not convinced of a definite causal link between smoking and lung cancer.²⁵ The problem with epidemiological studies was that some form of bias from the researchers or unexpected variables could obscure the certainty of the causal relation. Arguments of bias and statistical manipulation were not easily countered.²⁶ Statisticians like Joseph Berkson and Sir Ronald Fisher observed that the flawed memory of patients could not serve as a basis for causal explanation.²⁷ Professor emeritus of surgery Evarts Graham of Washington University,²⁸ who had quit smoking, attributed much of this scepticism to the fact that many medical professionals themselves still smoked and were therefore blind or unwilling to acknowledge the association.²⁹ Critics, of whom the tobacco industry was the most vocal, warned against a headlong acceptance of the merely statistical relation between smoking and lung cancer. A statistical relation should not be accepted as a definite cause, the cigarette companies argued.³⁰ Was a statistical relationship enough to explain such a complex non-infectious chronic disease as lung cancer? Could statistical correlation proof that A was the sole active cause of B? Doll and Hill and their American counterparts Wynder and Graham continued to produce study after study with a complex amount of variables which demonstrated the causal relationship between smoking and cancer. Still critics persevered in asserting that no single study could conclusively demonstrate a causal relationship between smoking and cancer.³¹ The issue of the “causal conundrum” was rather humorously addressed by Evarts Graham in The Lancet of 1954:

We find that many thoughtful people believe that our experimental results bring to the statistical studies additional convincing evidence of an aetiological [causal] relation between excessive cigarette-smoking and bronchogenic carcinoma. There are others, however, who remain unconvinced. These ‘die-hards’ state that so far no proof of the relation has been presented. One must grant that indeed no absolute proof has been offered. But what sort of proof is called for? To satisfy the most obdurate of the die-hards it would be necessary to take the following steps:

1.

Secure some human volunteers willing to have a bronchus painted with cigarette tar, perhaps through a bronchial fistula.

 

2.

The experiment must be carried on for at least twenty or twenty-five years.

 

3.

The subjects must spend the whole period in air conditioned quarters, never leaving them even for an hour or so, in order that there may be no contamination by a polluted atmosphere.

 

4.

At the end of the twenty-five years they must submit to an operation or an autopsy to determine the result of the experiment.

 

I will say to those who wish to volunteer for such an experiment, ‘please form a queue to the right; no crowding please.’³²

Although the convincing epidemiological evidence was generally accepted by mid-twentieth century, dissenting voices remained. During several decades the industry maintained there was a scientific controversy on the causal relation between tobacco and lung cancer. I will return to this subject in the next chapter.³³

By the 1950s, chronic diseases had overtaken contagious and infectious diseases as the major cause of death in the largest part of the Western world. The identification of cigarettes as major health hazards was a critical turning point in the history of public health policy. Public health policies would shift their attention from infection control to non-communicable diseases.³⁴ This refocus of public health policy immediately caused questions on the nature of public health. Was it the task of public health institutions to regulate personal behaviours? Who would decide which habits were unhealthy? Up until then public health authorities had only been active in the control of communicable diseases, where their involvement was in the clear interest of the nation’s well-being. All other aspects of a person’s health had been the well-guarded provenance of the medical profession.³⁵ The different focus of public health officials sparked resistance and defiance by the medical profession against actions on tobacco use by the public health sector. Doctors accused the public health sector of handling beyond its own boundaries and within those of the medical profession.

Despite these tensions on professional border lines, a study group on smoking and health was organized in 1956. The commission was formed on the initiative of the U.S. Surgeon General, Leroy Burney. Members of the American Cancer Society, the National Heart Institute, the National Cancer Institute, and the American Heart Association met regularly to discuss the evidence on smoking and lung cancer. Epidemiological findings, animal studies, and pathological and histological studies all added evidence to strengthen the causal relationship.³⁶ The Surgeon General declared that the data on smoking and disease was convincing: “[t]he sum total of scientific evidence establishes beyond reasonable doubt that cigarette smoking is a causative factor in the rapidly increasing incidence of human epidermoid carcinoma of the lung.”³⁷ He furthermore declared that “there is increasing evidence that excessive cigarette smoking is one of the factors which can cause lung cancer.”³⁸

The Public Health Service (PHS) assessed its own role in informing physicians, who were generally confused on what to tell their patients about smoking. The PHS was divided on whether to “put the message out” or to “avoid a missionary statement.” Notwithstanding compelling demands for action from members of the National Cancer Institute, the PHS assigned itself a limited role in the discussion on smoking, in an attempt not to overstep their role vis-à-vis physicians.³⁹ The Journal of the American Medical Association (JAMA) published a defence of clinical authority: “[n]either the proponents nor the opponents of the smoking theory have sufficient evidence to warrant the assumption of an all-or-none authoritative position. Until definitive studies are forthcoming, the physician can fulfil his responsibility by watching the situation closely, keeping courant of the facts, and advising his patients on his appraisal of those facts.”⁴⁰ The squabble on professional territory with the American Medical Association (AMA) and the PHS, prevented the PHS to act against the dangers of smoking early on and in a decisive manner.⁴¹ The AMA, afraid to lose any professional domain, was furthermore against a congressional proposal to label tobacco products. “The answer that will do most to protect public health lies not in labelling … but in research”, explained F. Blasingame, chief executive of the AMA.⁴² The following year the AMA Education Research Fund received funding from the tobacco industry. The initial grant of $10 million assured the tobacco companies of the fervent endorsement of the medical association. And so even the AMA maintained that further research was necessary on the tobacco controversy.⁴³ The tobacco industry had found an unlikely ally in the American Medical Association.

In the following years pressure was building on the PHS to organize a commission on the matter of lung cancer and smoking. In the spring of 1962, President Kennedy was asked in a national press conference to comment on the idea. Kennedy was clearly not prepared for the question and his answer was unusually hesitant:

Reporter: Mr. President, there is another health problem that seems to be causing growing concern here and abroad, and I think this has largely been provoked by a series of independent scientific investigations, which have concluded that cigarette smoking and certain types of cancer and heart disease have a causal connection.

I have two questions. Do you and your health advisors agree or disagree with these findings, and secondly, what if anything should or can the Federal government do in the circumstances?

President Kennedy: The a – That Matter is sensitive enough and the stock market is in sufficient difficulty – [laughter] – without my giving you -a- an answer which is not based on complete information, which I don’t have, and therefore perhaps we could – I would be glad to respond to that question in more detail next week.⁴⁴

Two weeks later, Kennedy’s Surgeon General Luther Terry, a PHS veteran, announced the establishment of a committee fully equipped to investigate the controversy on smoking and health.⁴⁵ The committee would have ten members. Terry proved also politically adequate when he included smokers as well as non-smokers in the committee. In addition, independent researchers and others who were involved with the tobacco industry were selected. The way the committee was selected, pre-emptively neutralized possible attacks of bias simply because the committee was compromised of members who represented both sides of the debate on the health risks of smoking.⁴⁶ The selection process also ensured the presence of a variety of disciplines, confirming the notion that the determination of causality required a wide variety of medical and scientific perspectives.⁴⁷ The assignment of the U.S. Surgeon General’s Advisory Committee was clear: to determine the “nature and magnitude of the health effects of smoking.”⁴⁸