Less education associated with faster aging and health inequality

A new study by USC Leonard Davis School of Gerontology researchers shows that Americans with less education are aging faster than their peers with more schooling, and the gap has grown over the last 30 years.

The study examined "biological aging," which goes deeper than simply counting birthdays. Biological aging measures how the body is changing over time, including how well organs and systems are working. For example, two people who are both 65 may look very different inside: one may have the biological profile of someone younger, while another may show signs of aging earlier.

Biological age gives us a clearer picture of health than chronological age. It helps us understand who is likely to stay healthy longer and who may be at higher risk for disease and disability."

Eileen Crimmins, study's senior author, USC University Professor 

A widening divide

Using data from the National Health and Nutrition Examination Survey, the team looked at adults ages 50 to 79 across two periods: 1988–1994 and 2015–2018. They found that while biological aging slowed for everyone, the benefits were significantly greater for people with more education.

For example, in the late 1980s and early 1990s, the difference in biological aging between adults with less than a high school education and those with a college degree was about one year. By 2015–2018, the gap had nearly doubled to two years.

"This means that people with more education have slower biological aging than everyone else," said Mateo Farina, assistant professor of human development and family sciences at the University of Texas at Austin, former USC Leonard Davis School postdoctoral researcher, and first author of the study. "The improvements we see in population health are not being shared equally."

Increasing inequality in health based on education has been a public health concern since the 1990s. The authors noted that this new study is among the first to evaluate whether the increased educational inequalities in physical health are linked to widening differences in biological age.

Why education matters

Education influences many aspects of life that affect health: the kinds of jobs people can get, how much money they make, where they live, and the health care they can access. More education also tends to correlate with healthier behaviors, such as smoking less and exercising more.

The study tested whether changes in smoking, obesity, or medication use explained the growing gap in aging. But the results showed that these factors did not account for the widening inequality; instead, differences tied directly to education itself appear to play the biggest role.

"Education shapes opportunities and risks throughout life," Crimmins explained. "It's a powerful social determinant of health, and it is leaving a mark on how fast or slow our bodies age."

The findings suggest that educational inequality could have major consequences for future generations of older adults. People with less education may not only die younger but may also spend more years in poor health, posing challenges to families, communities, and health systems.

"This isn't just a matter of individual choice; it's a social issue," Farina said. "If we want to reduce health disparities, we need to think about education as a public health investment."