An extra year of mandatory schooling reduced dementia diagnoses by 0.88 percent over the following 50 years, according to a new analysis of a major UK health study. Researchers at the University of Wisconsin–Madison and the University of Southern California, Los Angeles analyzed more than 100,000 participants in the UK Biobank to measure the long-term effects of a 1972 education reform that raised the minimum school-leaving age from 15 to 16.
The study traced the impact of the reform on people born after September 1, 1957, who were required to stay in school an extra year. The change increased the number of students attending through age 16 by 14 percent. The researchers obtained dementia diagnoses from multiple sources, including medical histories, hospital records, and death registries, to reduce bias that could skew results toward individuals who obtained diagnoses during life.
The reduction in dementia was more pronounced for participants carrying specific genetic variants that increase Alzheimer's disease and Alzheimer's disease-related dementia (ADRD) risk. The study was published in the Proceedings of the National Academy of Sciences on October 23, 2026.
"There are few preventative options out there so even one could make a world of difference," said lead author Silvia Barcellos, a health economist at the University of Wisconsin–Madison. The researchers also tied the education reform to improvements in socioeconomic factors and other health realms, suggesting potential avenues through which education can mitigate dementia risk. They cautioned, however, that differences between groups may shift as the study cohort continues to age and dementia diagnoses become more prevalent.