Optimizing Health in Aging Societies

Abstract

Aging societies reflect a triumph of science and technology over premature death. In less than a century, technologi- cal and medical advances—coupled with large-scale public health efforts that improved sanitation, purified water- ways, and increased safety—led to substantial improve- ments in the health of the U.S. population. The first half of the twentieth century witnessed gains in life expectancy largely due to reductions in infant and maternal mortality. Success was astounding. In a single century, infant mor- tality decreased by 90% and maternal mortality decreased by 99%. In the second half of the century, life expectancy continued to increase in adulthood, largely due to medical advances, in the treatment of cardiovascular disease. All told, nearly 30 years were added to average life expectancy in a single century. Increases continue today, with 3 months added to life expectancy at 65 every year. The magnitude of these changes is a testament to the potential of culture to alter physical functioning. Compared to our ancestors at the turn of the twentieth century, we are taller, stronger, and heartier. Our brains process informa- tion faster; and we live a lot longer. Agricultural advances insured a steady food supply. Electricity became ubiquitous and enabled refrigeration and heating. Efficient disposal of waste—garbage collection—and water purification starkly decreased exposure to pathogens in everyday life. Pasteurization and food fortification improved dietary intakes. Medical advances identified the causes of diseases and how they were spread. Immunization programs began to eradicate diseases that plagued earlier generations. As children survived, fertility fell and these two phe- nomena together reshaped the distribution of age in the populations (Becker & Barro, 1988). With fewer children and longer lives, entire societies began to age. In 2012, for the first time in history, the U.S. population included more people over 60 than under 15 years old. The once-universal pyramid shapes of age distributions—which characterized populations in every country around the world—are being rectangularized throughout the western world, reflecting the fact that most people, not just an exceptional few, are living into old age.