Four key factors that may underlie long life expectancy.
A 2017 Lancet study led by Majid Ezzati, adjunct professor of global health, predicted future life expectancy in 35 industrialized nations. Among the key findings: Life expectancy is projected to rise in all the countries studied; the largest increase in life expectancy will be in South Korea, and one of the smallest in the United States; and most of the gains will be due to greater longevity in older individuals rather than higher rates of childhood survival, as was the case historically.
“Why are some countries doing better than others in life expectancy gains? It comes down to four things, although a high-life-expectancy country may not necessarily meet all four criteria. One is social equity: In general, inequalities tend to be bad for health, and the U.S. is obviously the extreme. When you have high levels of inequality, it shapes health through the whole life course, from child mortality to conditions in old age—and therefore, it affects life expectancy. Second is health care access and quality: South Korea, for example, was very good at uptake of advanced medical knowledge and technology and at making sure those were available to everybody. Medical technology doesn’t have to be clinical medicine—it can be treatment guidelines that increase early detection, which helps people who are at risk of being sick to be diagnosed and treated early. Third is early childhood care and nutrition—people need a good start at life. And fourth is controlling the classical risk factors: tobacco, blood pressure, obesity, and so on.
As late as the turn of the 21st century, some people were saying that life expectancy of 90 years is unachievable. But we showed there is at least a 50 percent chance that South Korean women will soon cross that threshold—and I am completely convinced that age 90 is not a biological limit. Another important finding from the study is that some places are doing remarkably well and others are not. South Korea, some of the southern European countries, and some of the emerging economies in central Europe, for example, are seeing big increases in life expectancy. In the so-called English-speaking countries, Canada and Australia are doing better than the U.S.
All of these beneficial factors are, of course, a matter of social values and political decision making. There are things that governments should do and do well. Providing the conditions for long life expectancy is one of those.”