Research: The Smoking Woman

Throughout the 15-year wrangle over the effects of smoking on health, women smokers have offered a medical conundrum. Although they puff at cigarettes with the same freedom as men, they do not suffer as much lung cancer. Why?

The answer, Statistician E. Cuyler Ham mond of the American Cancer Society reported last week, is devastatingly sim ple: for all their freedom, modern wom en do not smoke as much as men. On the average, they do not start smoking as young, do not inhale as deeply, and have not smoked for as many years. Hammond's statistics also show, however, that the closer women's smoking practices approach men's, the closer are their disease and death rates.

In a detailed comparison of the smoking and health histories of 441,000 men and 563,000 women, Dr. Hammond's crew of epidemiologists followed the medical history of their volunteers since the winter of 1959-60. The first result of their work was the world's most exhaustive survey of the relationship between men's smoking and disease (TIME, Dec. 13, 1963), a study that was a major factor in persuading the U.S. Public Health Service to condemn smoking. By now, the Cancer Society researchers have followed both the men and the women for four years, and have tracked down the cause in 97% of the 43,000 deaths among the subjects. The delay in reporting the data on women reflects the fact that female death rates from virtually all causes are lower than the death rates among males; the Hammond staff had to wait for enough women to die to give them a valid statistical sample.

Three Factors. More men than women smoke cigarettes (47% of men aged 35 and up, as against 27% of women), and the disparity in smoking habits is notably greater in the older age groups. In the 35-44 age group (the youngest for which data on smoking and health are meaningful), women who limit themselves to less than half a pack a day outnumber men 3 to 1; those who stop at a pack a day outnumber men 2 to 1. Deep inhaling is half as common among the 35-44 women as among men, and only one-third as common in the 55-64 age bracket.

The sampling of current smokers shows that as recently as the 1930s, only one-third as many girls as boys started smoking before they were 15; this is significant because disease and death rates, notably for lung cancer, are related to duration of smoking. All three factors —age of starting, inhalation habits and number of cigarettes smoked—said Dr. Hammond, tend to go together: a boy or a girl who starts smoking before age 15 is more likely to become a heavy smoker and deep inhaler.

Women smokers in the 45-54 age group, Hammond's statistics show, have a death rate 1.31 times higher than that of nonsmokers. And the rate goes up with the number of cigarettes smoked: it is 1.54 times the rate for nonsmokers among women in the one-to-two-packs-a-day range, and 1.96 times as high for those using more than two packs a day. The mortality rates follow practically the same patterns when computed in relation to depth of inhaling and age at which smoking began.