The Diploma Dividend Study: One Extra Year of School Cuts Dementia Risk

When lawmakers in England, Wales and Scotland raised the school-leaving age from 15 to 16 in 1972, they were thinking about jobs and opportunity, not brains. Fifty years later, that one extra year of school appears to have lowered dementia diagnoses. The benefit was greatest for people whose genes put them at higher risk of Alzheimer's disease.

In a new NIH-funded study of more than 100,000 people, researchers found some of the strongest evidence yet that education does more than track with lower dementia risk. It may actually help cause it. For teachers, parents, public leaders and anyone who has watched a loved one fade, this suggests something hopeful: the decisions we make about schools today could shape the health of whole communities for generations.

This novel study provides perhaps the strongest evidence yet that education can help mitigate long-term dementia risk. Led by researchers at the University of Wisconsin–Madison and the University of Southern California, Los Angeles, the analysis demonstrates that an education reform in the United Kingdom, which extended the minimum drop-out age by a year, reduced dementia incidence up to 50 years later. Study participants whose genetics placed them at higher risk of developing Alzheimer’s Disease (AD) and AD-Related Dementias (ADRD) benefited most from the reform. 

“These findings reinforce the understanding that dementia risk is determined by factors beyond one’s genetic makeup and that changes such as additional schooling can offset inherited vulnerability,” said Richard Hodes, M.D., director of NIH’s National Institute on Aging (NIA). 

Higher levels of education being linked to reductions in dementia risk is not a novel idea. In fact, the two have a long-documented correlative relationship. However, scientists have struggled to determine whether this link is causal. Doing so would require comparing an intervention to a control in a large population of students and following them for an extended period. Coincidentally, a law enacted in England, Wales, and Scotland in 1972 afforded researchers this type of opportunity. 

A compulsory education reform in the UK raised the minimum age at which students could drop out of school from 15 to 16, affecting students who were born after Sept. 1, 1957. The change led to a 14% increase in the number of students enrolled in school until they reached 16. To gauge the impact of this bump on long-term AD/ADRD incidence, the authors analyzed medical data from more than 100,000 participants in a large aging cohort, the UK Biobank. 

Diagnoses made before December 2022, when the oldest study participants became 65, served as the primary point of comparison between groups who were affected or unaffected by the educational reform. Importantly, the researchers obtained diagnoses from multiple sources, including medical histories, hospital records, and death registries, to limit the impact of survival and other biases that could skew the data toward individuals capable of obtaining diagnoses during life.

This NIH-funded study showed the effect was profound, especially among those at elevated genetic risk.

The researchers found that the additional year of school reduced AD/ADRD incidence over the following 50 years by .88% — a considerably large effect given that overall rates of dementia in the study population were low. This signal was strongest for high-risk participants carrying specific genetic variants known to increase AD/ADRD incidence. 

They also tied the reform to improvements in socioeconomic factors and other realms of health, hinting at potential avenues by which education can mitigate dementia risk. While the findings support the argument that increases in education mitigate dementia later in life, the authors express caution when interpreting the results because participant age was capped at 65. As the study cohort continues to age and dementia diagnoses become more prevalent, differences between groups may become larger or smaller with time. 

“The message here is less about the specific numbers and more about the nature of education’s connection to dementia. There are few preventative options out there so even one could make a world of difference,” said lead author Silvia Barcellos, Ph.D., a health economist at UW–Madison. 

Reference

Reference: Silvia H. Barcellos, et al. Education Reduces Dementia Incidence and Mitigates Genetic Risk. Proceedings of the National Academy of Sciences. October 23, 2026. DOI: 10.1073/pnas.2529506123 

Attribution

Source: National Institutes of Health (October 23, 2026). The headline and introduction are CityGov's own and are not endorsed by NIH.

NIH supported this research through NIA grants R01AG078522, K01AG0669991, RF1AG055654, R56AG058726, and R00AG062787.