Want to live longer? Stay in school
February 20, 2020
Science Daily/Yale University
A multi-institution study has attempted to tease out the relative impact of two variables most often linked to life expectancy -- race and education -- by combing through data about 5,114 black and white individuals in four US cities.
Life expectancy in the United States has been in decline for the first time in decades, and public health officials have identified a litany of potential causes, including inaccessible health care, rising drug addiction and rates of mental health disorders, and socio-economic factors. But disentangling these variables and assessing their relative impact has been difficult.
Now, a multi-institution study led by the Yale School of Medicine and University of Alabama-Birmingham has attempted to tease out the relative impact of two variables most often linked to life expectancy -- race and education -- by combing through data about 5,114 black and white individuals in four U.S. cities.
The lives and deaths among this group of people -- who were recruited for a longevity study approximately 30 years ago, when they were in their early 20s, and are now in their mid-50s -- shows that the level of education, and not race, is the best predictor of who will live the longest, researchers report Feb. 20 in the American Journal of Public Health. The individuals were part of the Coronary Artery Risk Development in Young Adults (CARDIA) study.
Among the 5,114 people followed in the study, 395 had died.
"These deaths are occurring in working-age people, often with children, before the age of 60," said Yale's Brita Roy, assistant professor of medicine and epidemiology and corresponding author of the paper.
The rates of death among individuals in this group did clearly show racial differences, with approximately 9% of blacks dying at an early age compared to 6% of whites. There were also differences in causes of death by race. For instance, black men were significantly more likely to die by homicide and white men from AIDS. The most common causes of death across all groups over time were cardiovascular disease and cancer.
But there were also notable differences in rates of death by education level. Approximately 13% of participants with a high school degree or less education died compared with only approximately 5% of college graduates.
Strikingly, note the researchers, when looking at race and education at the same time, differences related to race all but disappeared: 13.5% of black subjects and 13.2% of white subjects with a high school degree or less died during the course of the study. By contrast, 5.9% of black subjects and 4.3% of whites with college degrees had died.
To help account for differences in age-related mortality, the researchers used a measure called Years of Potential Life Lost (YPLL), calculated as projected life expectancy minus actual age at death. This measure not only captures numbers of deaths, but also how untimely they were. For example, someone who dies at age 25 from homicide accrues more YPLL than someone who dies at age 50 from cardiovascular disease. It would take two deaths at age 50 to equal the YPLL from a single death at age 25.
Even after accounting for the effects of other variables such as income, level of education was still the best predictor of YPLL. Each educational step obtained led to 1.37 fewer years of lost life expectancy, the study showed.
"These findings are powerful," Roy said. "They suggest that improving equity in access to and quality of education is something tangible that can help reverse this troubling trend in reduction of life expectancy among middle-aged adults."
https://www.sciencedaily.com/releases/2020/02/200220193449.htm
Education, not income, the best predictor of a long life
April 16, 2018
Science Daily/International Institute for Applied Systems Analysis
Rising income and the subsequent improved standards of living have long been thought to be the most important factors contributing to a long and healthy life. However, new research has shown that instead, the level of education a person has is a much better predictor of life expectancy.
In 1975, Samuel Preston developed the Preston Curve, which plotted the GDP per person on the horizontal axis against life expectancy on the vertical axis. The curve shows a clear but flattening upward trend in life expectancy with increasing GDP. The curves also shift upwards over time which has been explained by better healthcare.
In 1985, John Caldwell and Pat Caldwell suggested instead that lowered mortality resulted from better female education. In their new paper, Lutz and Kebede used global data from 174 countries from 1970-2015 to test the two hypotheses. Whether income or education is more important for improving health and life expectancy is an important question for policymakers deciding where to direct funding.
Lutz and Kebede also plotted life expectancy against the mean years of schooling of the adult population. The curve created is much more linear, suggesting that education is a much better predictor. There is no upward shift of the curve requiring explanation by other factors. Data was subject to multivariate analyses to validate the findings. The same link was found when the curves were adjusted for child mortality.
The researchers point out that better education leads to improved cognition and in turn to better choices for health-related behaviours. Recent decades have seen a shift in the disease burden from infectious to chronic diseases, the latter of which are largely lifestyle-related. As time goes on, the link between education and better health choices, and therefore life expectancy, will become even more apparent.
"This paper is more radical than previous analyses in terms of challenging the ubiquitous view that income and medical interventions are the main drivers of health. It even shows that the empirical association between income and health is largely spurious," says Lutz.
Previous lines of research at the Wittgenstein Centre, a collaboration between IIASA, WU and the Vienna Institute of Demography, have emphasised the importance of improving education for poverty eradication and economic growth, as well as the ability to adapt to climate change. These findings further back up the call for improved access to education.
The apparent link between health and income found by Preston can be explained by the fact that better education results in both better health and higher incomes.
"The findings matter for the entire global health research community, and they matter for everybody in global development and deciding on funding allocations for the different aspects of development," says Lutz, adding that funding quality education for all around the world should be a much higher priority.
https://www.sciencedaily.com/releases/2018/04/180416103428.htm