Effects Of Tobacco On Longevity
( Originally Published Early 1925 )
Tobacco affects different persons variously. Whether it causes arterio-sclerosis (the increase of connective tissue in the walls of arteries) or not we do see every day that persistent smokers lose too soon their youthful looks and complexion, a change especially conspicuous in women who have fallen into the cigarette habit.' There are good observers, among ]them Prof. Lazarus, of Berlin, who regard excessive smoking as one of the principal causes of arterio-sclerosis, and when we consider the effect of tobacco on 'the heart in some people, it appears natural that the smaller blood vessels are likewise injured by it. It is ruled out in the training camps of athletes where it is regarded as injuriously affecting the "wind."
When the class of '68 graduated from Dartmouth College, the secretary took a record of those using any alcoholic liquors and of those using tobacco. Fifty years afterward a summary was made of the death rate of the class. The average age at death for those who passed away during the 50 years was' 44 years 11 months for those who used liquor in college, and 63 years 6 months for those who did not, a difference of 18 years 7 months in favor of the non-users. During the first 25 years 29.4% of the users of liquor and 6.7% of the non-users had died. The average age at death for those who used tobacco was 49 years 9' months, while for those who did not it was 59 years 4 months, or nearly 10 years in favor of the non-user. Dated Hanover, N. H., December, 1919. Signed by Charles F. Emerson, Secretary, class of 1868.
The above report, believed to be credible, is not reproduced as meeting the requirements of a scientifically conducted investigation. A letter of inquiry developed the following additional facts: The secretary of the class was a man of high character and scholastic attainments. He was a member of the faculty from 1872 to 1899, rising from a tutorship in mathematics to professor of natural philosophy (1878), becoming also instructor in astronomy and, in 1893, dean of the faculty. For 20 years he de-voted his entire time to administrative work. Dr. Emerson not only had an intimate knowledge' of the individuals of the class of '68 but, we are informed, kept in touch with them. He died since the above information was obtained. The records of their habits as to alcohol and tobacco were entered by each man upon graduation in a class register.
In the Fisk fund prize dissertation on the Physiological and Pathological Effects of the Use of Tobacco (physiological, normal, as opposed to pathological, or conditions of disease) won by Hobart Amory Hare, M.D., now a distinguished member of the medical faculty of Jefferson Medical College, Philadelphia, the author devoted 92 printed pages to a study of the effects of 'tobacco on the normal human body and also on many lower animals (see index for footnote on Hare). The results of his experiments on animals were uniformly to the effect that nicotine in as small an injection as 1/32 of a drop caused death in 20 dogs by asphyxiation, death occurring invariably from stoppage of respiration, the heart continuing to pulsate for some minutes after breathing stopped.
Two tables are printed to show the effects on the pulse rate of a man not accustomed to the use of tobacco who smoked one cigarette and on one who was an inveterate user of tobacco. In five days' experimentation with the non-user 'he found that a cigarette smoked before breakfast caused an average rise in the pulse from 64 to 96 beats; before dinner, from 66 to 84; before supper from 65 to 92. In the case of the inveterate user, before breakfast, from 57 to 74; before dinner from 68 to 79; before supper from 67 to 73. For the five days a cigarette was smoked after breakfast caused an average rise in the pulse of the non-smoker from 65 to 85; after dinner from 70 to 76; after supper, from 66 to 73. For the inveterate user after breakfast, from 60 to 77; after dinner, from 74 to 85; after supper, from 66 to 72. Our author observes the curious fact that al-though in ;the case of the user of tobacco the eating of a meal increased the normal pulse rate, the increase of rate after smoking remained constant, 17, 11 and 6 beats respectively for breakfast, dinner and supper. Sphygmographic tracings ' (on a moving ribbon by an instrument part of which rests on the radial artery of the wrist) are printed to show to the eye the variations in the radial pulse before smoking and after
Instead of quoting Hare's conclusions adverse to the use of tobacco except by men of a phlegmatic temperament who live much in the open air and by old people who have become habituated to its use, we prefer to quote the standard United States Dispensatory, twentieth edition (1918), based on the United States Pharmacopeia and the British Pharmacopeia (1914) :
There is no room for doubt that nicotine is present in tobacco smoke in sufficient amount to be injurious. Lehmann 2 finds that about 95 per cent of the nicotine in tobacco passes into the smoke and Toth 3 has shown that a large proportion of nicotine exists in the smoke in uncombined state. The characteristic odor of ordinary tobacco is entirely different from that of fresh (tobacco) leaves, and must be owing to the 'generation of a new volatile principle. The alkaloid nicotine is a virulent poison. It primarily excites and secondarily paralyzes the ganglia (centers of nerve influence) upon the sympathetic nerves, (controlling the vital action of viscera and blood vessels), stimulates the intestinal muscles and, in sufficient quantities, has a paralytic action upon the motor nerves. The most important disturbances produced are in the digestive and circulatory organs. As a result of the disturbed innervation of the heart, palpitation and cardiac (heart) irregularities are common and the vascular contraction (of the arteries) is generally regarded as one of the causes of arterial degeneration. It should always be borne in mind that its active principle is absorbed readily by the skin (and hence probably by the lungs and the various membranes over which smoke passes when inhaled). In its action on the animal system nicotine is one of the most virulent poisons known. Small birds perish at the approach of a tube containing it. The percentage of nicotine in tobacco varies considerably—from 1.62 per cent in Havana tobacco to 2 per cent in Maryland tobacco, 6 in Virginia tobacco and 8 in Kentucky tobacco.
The smoker's cough and its accompanying pharyngitis is usually associated with laryngeal irritation and hyperesthesia (excessive sensitiveness) of the larynx 2 (the organ of the voice). That part of the pharynx here referred to lies adjacent to and behind the larynx.
Huchard, of Paris thought tobacco an important cause of arterio-sclerosis (degeneration and hardening of the arteries) and that it also causes heart enervation (weakness). ,Kreuznach, of Vienna, has shown recently that nicotine produces arterio-sclerosis. Hurst says nicotine is probably the cause of the relaxing effect produced by moderate smoking and of the tendency to colon spasm when an excessive quantity of tobacco is smoked. Mr. C. H. smoked on an average 4 large cigars, 3 pipes and 6 cigarettes a day. He had colicky abdominal pains and a frequent desire to urinate and defecate. A stricture was found in the rectum and a similar one somewhat higher up. Mr. M., a constant pipe smoker, had abdominal discomfort of fulness in the upper part of the descending colon.
A frequent phrase used in connection with the use of tobacco is "tobacco heart." Exactly what this is Brooks explains. He noticed years ago that old soldiers, tobacco users, up for reenlistment were frequently rejected for irregular and inadequate heart action. Kept off tobacco for a short time most of them would pass. As a medical officer of a National Guard regiment he had practically the same experience. The record of private patients was very similar. His interest in the cause and prevention of heart disease finally led him to make 54 postmortems where death seemed to bear a relation to the use of tobacco. Of these 17 showed marked hardening of the arteries of the heart (coronary sclerosis) and 19 the same change in a lesser or slight degree. In 37 cases—just one more than presented disease of the heart arteries—there was chronic inflammation of the lining membrane of the heart (endocarditis), which may have been the cause of the diseased arteries?
Observations of many instances of,"tobacco heart" by our author caused him to reach the conclusion that in all probability the elemental condition in tobacco heart is one of arterial spasm affecting 'coronary vessels (arteries of the heart). Similar conditions affecting other arteries, as those of the leg and arm, probably also those of the pancreas, were observed in tobacco poisoning. Complete relief followed the giving up of tobacco. Angina pectoris (breast pang, with a feeling of suffocation, caused by arterial spasm) is a frequent symptom with old tobacco users. It sometimes cannot be relieved by quitting tobacco. Yet there was no definite condition of this kind found in the 36 cases of definite hardening of the heart arteries found in the 54 post-mortems, cited above. On the other hand it is important to state that 18 of those cases gave a history of more or less indefinite heart disturbance and 12 cases died a cardiac death (from heart disease). Hirschfelder says the most serious effects are produced in the young from cigarette smoke when inhaled, which, our author thinks, can be explained by the greater sensitiveness of the tissues of the young.
Brooks distinguishes between true angina and tobacco angina. The former cannot be relieved by the non-use of tobacco while the latter can be. Death may result from acute tobacco poisoning and from tobacco angina but the latter case is probably very rare and most likely only occurs when diseased heart arteries preexist. He recommends moderation in smoking.