More recent generation showed greater death rate disparity related to education.
The conclusion adds: "Existing research suggests that a substantial part of the association between education and mortality is causal."
The authors say that increasing levels of education could significantly reduce adult death rates in the US.
The mechanisms cited by which higher educational attainment is linked to reduced death risk include:
- Higher income and social status
- Enhanced cognitive development
- Adherence to medical treatments
- Healthier behaviors
- Improved social connections and psychological wellbeing.
Dr. Virginia Chang, associate professor of population health at New York University School of Medicine, says:
"In public health policy, we often focus on changing health behaviors such as diet, smoking and drinking.
Education - which is a more fundamental, upstream driver of health behaviors and disparities - should also be a key element of US health policy."
The authors conclude: "Our results suggest that policies and interventions that improve educational attainment could substantially improve survival in the US population, especially given widening educational disparities across birth cohorts."
The researchers used data from the National Health Interview Survey carried out by the Centers for Disease Control and Prevention.
Data enabling an estimate of the number of deaths attributed to low levels of education were available on more than a million people from 1986 to 2006. The team studied people born in 1925, 1935 and 1945 to look at changes over the generations.
The results showed that 145,243 deaths could have been saved in the 2010 population if adults who had not completed high school went on to earn a General Educational Development or high school degree.
This figure was comparable to the estimated number of deaths that could be averted if all current smokers had the mortality rates of former smokers.
The team also estimated that 110,068 deaths could be saved if adults with some college education went on to complete a bachelor's degree.
The differences in death rates across different levels of education grew substantially over time, say the researchers.
For example, mortality rates fell modestly among those with high school degrees, but much more rapidly among those with college degrees. Therefore, encouraging adults who have not finished high school to do so could save twice as many lives among those born in 1945 compared with the generation born in 1925.
Patrick Krueger, PhD, assistant professor in the department of health and behavioral sciences at the University of Colorado Denver, says:
"Our results suggest that policies and interventions that improve educational attainment could substantially improve survival in the US population, especially given widening educational disparities.
"Unless these trends change, the mortality attributable to low education will continue to increase in the future."