Why Do the Educated Live Longer?

The better educated you are, the longer you are likely to live. What are the reasons for the educational disparity in mortality? A study published in the journal Demographic Research investigated the contribution of one factor: the greater prevalence of obesity among the less educated.

Previous studies have shown obesity to have little effect on differences in life expectancy by educational attainment, but researcher Yana C. Vierboom takes issue with those studies because their measure of obesity is body mass index (BMI) at the time of the survey. This introduces bias into the results, says Vierboom, "given that less educated people are more likely to contract illnesses that induce weight loss." Instead, lifetime maximum BMI is a better measure of obesity.

Using lifetime maximum BMI, Vierboom finds obesity to be an important contributor to the educational disparity in mortality. "Differences in maximum BMI were associated with between 10.3% and 12% of mortality differences between college graduates and all others," she says. Among nonsmokers, between 18.4% and 27.6% of mortality differences between college graduates and all others were associated with differences in maximum BMI."

Source: Demographic Research, The Contribution of Differences in Adiposity to Educational Disparities in Mortality in the United States