A systematic review and meta-analysis published in the Lancet suggests that more years of education is linked to reduced all-cause mortality in adults [1].
Benefits of education
Educational attainment is associated with better health and improvements in some measurements of mortality. One example is parental education. Research has found that each year of paternal education reduces the mortality risk of a child under five years of age by 1.6%. For maternal education, the benefit is almost twice as high, as each year of maternal education reduces such risk by 3% [2].
However, while educational attainment is a well-known confounder in mortality studies, the authors note that there is no study that has systematically quantified its impact on mortality among adults.
Study long, live long
The authors searched seven databases to identify scientific papers published between January 1, 1980, and June 16, 2023. To be included in the analysis, publications had to report individual-level data of years of schooling and all-cause mortality.
The search found 17,094 unique records. However, after excluding the studies that didn’t meet the inclusion criteria, only 603 were eligible for analysis. The dataset created based on those studies had 10,355 observations.
The authors put no restrictions on where these studies were located, aiming for this to be a global analysis. They identified studies from 70 locations in 59 countries. However, they also noted that over 85% of these studies were from high-income regions, while no studies were from North Africa nor the Middle East. In this analysis, the authors controlled for variables like age, sex, and marital status and compared people with various educational attainment levels.
The analyzed data showed that obtaining education is good for longevity. When the authors compared people with no education to those who completed 6 years of education, they observed a 13.1% reduction in mortality risk. Completing an additional 6 years of school (12 years total) resulted in a 24.5% lower mortality risk compared to people with no education at all.
For the most highly educated people in this analysis, those who completed 18 years of school, the mortality risk was the lowest. When they were compared to people with no education, their mortality risk was 34.4% lower.
The authors note that this can be translated to “an average reduction in mortality risk of 1.9%” per each year of schooling; however, that differs by the age group. For people between 18 and 49 years old, each year of schooling reduced the mortality risk by 2.9%, but for people aged 70 and older, the benefit of each year of schooling meant a mortality risk reduction of 0.8%. There were no differences between males and females.
A smaller impact of educational attainment on mortality risk in older life can be explained by the higher impact of other factors, like genetic disposition or daily habits, on mortality risk at that age.
Lack of education is as bad as smoking or lack of exercise
To put those numbers into context, the authors compared education to different health-related behaviors that impact mortality. For example, the relative mortality risk between people who have 18 years of education and those with no education is comparable to the relative risk of ischaemic heart disease between people who have optimal vegetable consumption and people who don’t eat vegetables [3] and to the relative mortality risk of adults who meet physical activity guidelines for aerobics and strengthening and those who don’t [4].
Lacking education can also be compared to smoking or drinking alcohol. The mortality risk of a person with no education compared to a person with 18 years of schooling is comparable to “that of lung cancer incidence or mortality for a person who currently smokes (5 pack-years) compared with a person who has never smoked” [5] or the mortality risk difference between a high-volume alcohol drinker and an occasional drinker [6].
Better education, better opportunities
The authors note that the effect of education on mortality risk is due to the different opportunities and behaviors of educated people.
Educated people have “access to better employment, higher earnings, quality health care, and increased health knowledge” [7]. They also “tend to develop a larger set of social and psychological resources that shape the health and duration of their life” [8,9].
In summary:
We found that years of schooling had a significant and consistent effect on all-cause mortality risk and the protective effect of education persisted for female and male individuals, across all age groups, and all levels of Socio-demographic Index of the country where the data were collected. These findings are similar to the protective effects of a good diet and physical activity and the harms of risk factors such as smoking and alcohol.
Literature
[1] IHME-CHAIN Collaborators (2024). Effects of education on adult mortality: a global systematic review and meta-analysis. The Lancet. Public health, S2468-2667(23)00306-7. Advance online publication.
[2] Balaj, M., York, H. W., Sripada, K., Besnier, E., Vonen, H. D., Aravkin, A., Friedman, J., Griswold, M., Jensen, M. R., Mohammad, T., Mullany, E. C., Solhaug, S., Sorensen, R., Stonkute, D., Tallaksen, A., Whisnant, J., Zheng, P., Gakidou, E., & Eikemo, T. A. (2021). Parental education and inequalities in child mortality: a global systematic review and meta-analysis. Lancet (London, England), 398(10300), 608–620.
[3] Stanaway, J. D., Afshin, A., Ashbaugh, C., Bisignano, C., Brauer, M., Ferrara, G., Garcia, V., Haile, D., Hay, S. I., He, J., Iannucci, V., Lescinsky, H., Mullany, E. C., Parent, M. C., Serfes, A. L., Sorensen, R. J. D., Aravkin, A. Y., Zheng, P., & Murray, C. J. L. (2022). Health effects associated with vegetable consumption: a Burden of Proof study. Nature medicine, 28(10), 2066–2074.
[4] Zhao, M., Veeranki, S. P., Magnussen, C. G., & Xi, B. (2020). Recommended physical activity and all cause and cause specific mortality in US adults: prospective cohort study. BMJ (Clinical research ed.), 370, m2031.
[5] Dai, X., Gil, G. F., Reitsma, M. B., Ahmad, N. S., Anderson, J. A., Bisignano, C., Carr, S., Feldman, R., Hay, S. I., He, J., Iannucci, V., Lawlor, H. R., Malloy, M. J., Marczak, L. B., McLaughlin, S. A., Morikawa, L., Mullany, E. C., Nicholson, S. I., O’Connell, E. M., Okereke, C., … Gakidou, E. (2022). Health effects associated with smoking: a Burden of Proof study. Nature medicine, 28(10), 2045–2055.
[6] Zhao, J., Stockwell, T., Naimi, T., Churchill, S., Clay, J., & Sherk, A. (2023). Association Between Daily Alcohol Intake and Risk of All-Cause Mortality: A Systematic Review and Meta-analyses. JAMA network open, 6(3), e236185.
[7] Baker, D. P., Smith, W. C., Muñoz, I. G., Jeon, H., Fu, T., Leon, J., Salinas, D., & Horvatek, R. (2017). The Population Education Transition Curve: Education Gradients Across Population Exposure to New Health Risks. Demography, 54(5), 1873–1895.
[8] Phelan, J. C., Link, B. G., & Tehranifar, P. (2010). Social conditions as fundamental causes of health inequalities: theory, evidence, and policy implications. Journal of health and social behavior, 51 Suppl, S28–S40.
[9] Thoits P. A. (2010). Stress and health: major findings and policy implications. Journal of health and social behavior, 51 Suppl, S41–S53.
