The Correlation Between Education and Life Expectancy
It is comparatively easy to find correlations in human epidemiological data, but much harder to determine causation. A web of correlations exist between socioeconomic status, education, intelligence, and life expectancy. We can even draw in environmental factors such as degree of exposure to particulate air pollution, which tends to correlate with the wealth of individuals living in a given area. In the matter of education, the effect size is small but the correlation is robust in large data sets. Why this is the case remains a topic for discussion.
To measure the pace of aging, the researchers applied an algorithm known as the DunedinPACE epigenetic clock to genomic data collected by the Framingham Heart Study. The latest findings showed that, according to the yardstick of the DunedinPACE epigenetic clock, two years of additional schooling translated to a 2-3% slower pace of aging. This slowing in the pace of aging corresponds to a roughly 10 percent reduction in risk of mortality in the Framingham Heart Study, according to previous research on the association of DunedinPACE with risk of death.
The researchers used data from 14,106 Framingham Heart Study spanning three generations to link children's educational attainment data with that of their parents. They then used data from a subset of participants who provided blood samples during data collection to calculate the pace of biological aging using the DunedinPACE epigenetic clock. In primary analysis, the researchers tested associations between educational mobility, aging, and mortality in a subset of 3,101 participants for whom educational mobility and pace of aging measures could be calculated. For 2,437 participants with a sibling, the researchers also tested whether differences in educational attainment between siblings were associated with a difference in the pace of aging.
"A key confounder in studies like these is that people with different levels of education tend to come from families with different educational backgrounds and different levels of other resources. To address these confounds, we focused on educational mobility, how much more (or less) education a person completed relative to their parents, and sibling differences in educational attainment - how much more (or less) education a person completed relative to their siblings. These study designs control for differences between families and allow us to isolate the effects of education."
By combining these study designs with the new DunedinPACE epigenetic clock, the researchers were able to test how education affects the pace of aging. Then, by linking the education and pace of aging data with longitudinal records of how long participants lived, the team was able to determine if a slower pace of aging accounted for increased longevity in people with more education. "We found that upward educational mobility was associated both with a slower pace of aging and decreased risk of death. In fact, up to half of the educational gradient in mortality we observed was explained by healthier aging trajectories among better-educated participants." This pattern of association was similar across generations and held within family sibling comparisons: siblings with higher educational mobility tended to have a slower pace of aging as compared with their less educated siblings.
Link: https://www.publichealth.columbia.edu/news/more-schooling-linked-slowed-aging-increased-longevity