A Longer, Healthier (?) Life

Last week, the United Nations released its biannual population projections (World Population Prospects: The 2006 Revision). In it, the UN reported something that we are painfully aware of: we are getting older. The U.S. is the only major developed country that is not yet aging, and the UN projections indicate that one in four people in the world will be over 60 in 2050.

The demographic transition from high fertility and high mortality to low fertility and low mortality is reaching its final stages in many developed countries, where few babies are born, ever greater numbers of people move into retirement, and the "old age dependency ratio" (e.g. number of people over 65 relative to the number of working age people) rises. In Europe, where the dearth of babies has been called a "crisis," policies are being tried to increase fertility rates, while developing countries - where global population growth is concentrated - still need to bring down fertility rates in order to reach the late stage of the demographic transition.

Aside from buying call options on Geritol and reading glasses, what can we do to postpone the unpleasant health effects of an aging population? Chronic diseases have long been considered "old people's diseases," and many do get diagnosed most frequently among the aged or near-aged. Hypertension, heart disease, "adult-onset" diabetes, and some cancers are all more likely to cause disability and death after age 60, particularly in rich countries. However, a growing older population, and increases in these diseases among the young and middle-aged constitute a double whammy to health systems in rich and poor countries alike. Developing countries are facing sudden and dramatic increases in chronic diseases. In fact, because many chronic diseases are emerging at earlier ages, even as people are living longer lives, the burden of chronic disease has become heavy for countries across the income spectrum and will continue to rise.

The best hope for reducing the chronic disease burden on health systems, macro-economies, and societies is to identify and implement cost-effective, workable prevention interventions, particularly in the areas of the three major chronic disease risk factors: unhealthy diet, lack of physical activity, and tobacco use. People will still be getting older, but they can also stay healthy well into old age.