1930-1950 Evidence Mounts Linking Cigarettes and Cancer
Health Claims for Cigarettes
Doctors Using Cigarettes
While the industry touted health claims, early in the 20th century physicians and researchers were alarmed by the increasing incidence of cancer in the U.S. population. Doctors and statisticians noticed similarly dramatic increases in lung cancer deaths among United States adult men. A researcher reported a 45% increase mortality rate from cancer per 100,000 people from 1900 to 1924 and:
The increase in the reported mortality rate of malignant disease has been so obvious in late years as to attract considerable popular attention, and to cause much alarm especially to the lay public. That this increase is a very real one is shown by the comparison of the crude figures for 1900, 63.0 per 100,000 population, with those of 1924, 91.9 per 100,000. (Eggers 9)
In these early days scientists looked at many possible causes of the increase of cancer, including: better diagnosis and reporting meant that cancer was more often found but not necessarily increasing, chemical exposure related to service in World War One, and toxic chemicals related to paved roads. Over decades of more research scientists began to discard other causes as smoking more and more was linked to cancer. In 1952, two researchers, E. Cuyler Hammond and Daniel Horn, working for the American Cancer Association, started the first major prospective study of 188,000 male smokers, providing the strongest evidence to date for cigarette smoking as a major cause of cancer. Participants, both smokers and non-smokers, were interviewed in 1952 and followed up with through 1955. When individuals in this group died during the study the cause of death was noted. Their first findings were published in 1958 in the Journal of the American Medical Association:
...it was found that the death rates were higher among regular cigarette smokers than among men who never smoked, that the mortality ratio increased with the number of cigarettes smoked per day, and that the death rates were higher among pipe and cigar smokes than among men who never smoked. men with a history of regular cigarette smoking have a considerably higher death rate than men who have never smoked or men who have smoked only cigars or pipes. (Eggers 1294)
The researchers found not only increased cancer of the lungs and larynx, but also increased incidence of flu, pneumonia, and coronary artery disease among others. While not many laypeople would read the Journal of the American Medical Association, more scientific reports finding ever stronger evidence of the link between smoking and cancer began to be reported in the popular press. In the early 1950's both Life Magazine and Reader's Digest published articles citing this research, bringing news of the link between cancer and smoking to a much wider audience than the medical literature had.
With research gaining more widespread exposure, the tobacco industry recognized a threat to sales and began a campaign to fight the science. This campaign would last for close to half a century until stopped by the U.S. court system.