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The United States has the world’s largest economy and spends more of its gross domestic product (GDP) on health care than most developed countries. Yet the United States has a lower life expectancy than many other wealthy countries—and the gap has been widening over the last two decades. New research shows that greater tobacco use among Americans is one cause of lower life expectancy. Although the prevalence of smoking has declined in the United States and many other countries since the 1970s, older Americans are still suffering the health effects of previous or current smoking habits—and this is reflected in their life expectancy.¹

Life Expectancy Improved Less in United States

Between the early 1950s and the 2005-2010 period, Americans gained an entire decade in longevity as life expectancy at birth rose from 68.9 years to 79.2 years. Yet life expectancy rose faster and to even higher levels in many other countries. It reached 80 years or more in Japan, Canada, and much of northern and western Europe. The United States dropped from 12th to 28th in the international ranking of life expectancy at birth since the 1950s.

The longevity gap also exists at older ages.² American women age 50 in 2006 can expect to live another 33 years, on average, but Japanese women can expect 37 additional years, and French women another 36 years.³ Although smoking contributes to deaths in all countries, it has been particularly devastating for Americans because of the U.S. history of heavy tobacco use.

Life Expectancy at Age 50 and Years of Additional Life Lost Because of Smoking, Selected Countries, 2003

Note: Countries are ranked by male life expectancy at age 50.
Source: Samuel H. Preston, Dana A. Glei, and John R. Wilmoth, “Contribution of Smoking to International Differences in Life Expectancy,” in International Differences in Mortality at Older Ages: Dimensions and Sources, ed. Eileen M. Crimmins, Samuel H. Preston, and Barney Cohen (Washington, DC: National Academies Press, 2010).

Americans Adopted Smoking Earlier

Why has smoking affected life expectancy more in the United States than other wealthy countries? Although smoking tobacco is now commonplace in much of the world, Americans were the first to adopt it on a broad scale, perhaps because they could afford it and because the United States is a major producer of tobacco cigarettes. Close to 70 percent of U.S. men born between 1910 and 1930 were regular smokers by age 35.

U.S. women also took up smoking, but they followed a different timetable and did not smoke as much as men until more recently. Women born between 1920 and 1950—who were ages 55 to 85 in 2005—were the heaviest smokers.

Smoking caught on later in the rest of the world, at different times in different countries. As the deleterious health effects became more widely known, and as governments adopted policies to reduce smoking, the practice has declined in many developed countries—also at very different rates. Smoking has dropped among both men and women in the United States. In 2008, about 23 percent of men and 19 percent of women age 18 or older were current smokers, according to a U.S. survey.⁴ Smoking rates are now higher in many developing and developed countries than in the United States.

Smoking and Lung Cancer

Smoking contributes to many diseases and health conditions, including heart disease, stroke, and cancer—the leading causes of death in many countries. But calculating the effect of smoking on mortality is tricky because many factors—obesity, stress, and genetics, for example—affect disease and mortality rates. Lung cancer is closely tied to smoking tobacco, making it a good proxy for the measuring the health damage resulting from smoking. About 90 percent of lung cancers among U.S. men—and about 70 percent among women—are attributed to smoking.

In a recent report sponsored by the National Academy of Sciences, demographer Samuel Preston and colleagues examined lung cancer mortality in the United States and 20 other high-income countries between 1950 and 2007 to estimate the proportion of deaths that could be attributed to smoking.⁵ They found that smoking more heavily influenced male than female deaths at age 50 or older, but that smoking-related mortality has been increasing among women.

In 2003, smoking had the greatest effect on male mortality in Hungary, among the countries studied. One-third of male deaths in Hungary were attributed to smoking, compared with about one-fourth of deaths for U.S. males. Among women, the United States bore the heaviest toll: Nearly one-fourth of female deaths in the United States were attributed to smoking.

If Americans and Europeans could erase their smoking histories, life expectancy at age 50 would be two to four years longer in many countries, according to this research (see table). And the United States would rank much higher in international comparisons. Preston and his colleagues estimated that—absent the health damage from smoking—U.S. male life expectancy at age 50 would rank ninth out of the 20 countries in their study, rather than its current rank of 14. U.S. women would boost their ranking much more: from 18th to seventh.

Because Americans have been successful in curbing the tobacco habit, lung cancer rates have begun to fall as lighter-smoking cohorts move into older ages. At the same time, lung cancer rates are increasing in the Netherlands and some other countries that adopted smoking well after it became common in the United States. Whether lower smoking and lung cancer rates will narrow the longevity gap among high-income countries will depend not only on smoking trends in the U.S. and other countries but also on mortality trends for other leading causes of death at older ages, such as heart disease, stroke, and other types of cancer.

References

1. Fred Pampel, “Divergent Patterns of Smoking Across High-Income Nations,” in International Differences in Mortality at Older Ages: Dimensions and Sources, ed. Eileen M. Crimmins, Samuel H. Preston, and Barney Cohen (Washington, DC: National Academies Press, 2010).
2. Eileen M. Crimmins, Samuel H. Preston, and Barney Cohen, “Introduction and Overview,” in International Differences in Mortality at Older Ages: Dimensions and Sources, ed. Eileen M. Crimmins, Samuel H. Preston, and Barney Cohen (Washington, DC: National Academies Press, 2010).
3. Dana A. Glei, France Meslé, and Jacques Vallin, “Diverging Trends in Life Expectancy at Age 50: A Look at Causes of Death,” in International Differences in Mortality at Older Ages: Dimensions and Sources, ed. Eileen M. Crimmins, Samuel H. Preston, and Barney Cohen (Washington, DC: National Academies Press, 2010): table 2-1.
4. John R. Pleis, Jacqueline W. Lucas, and Brian W. Ward, “Summary Health Statistics for U.S. Adults: National Health Interview Survey, 2008,” Vital and Health Statistics 10, no. 242 (2009), accessed at www.cdc.gov/nchs/data/series/sr_10/sr10_242.pdf, on Sept. 14, 2010.
5. Samuel H. Preston, Dana A. Glei, and John R. Wilmoth, “Contribution of Smoking to International Differences in Life Expectancy,” in International Differences in Mortality at Older Ages: Dimensions and Sources, ed. Eileen M. Crimmins, Samuel H. Preston, and Barney Cohen (Washington, DC: National Academies Press, 2010). See also The National Academies, “Current Projects: Understanding Divergent Trends in Longevity in High-Income Countries,” accessed at www8.nationalacademies.org/cp/projectview.aspx?key=48934, on Sept. 21, 2010.