An extra year of secondary school lowered dementia diagnoses later in life.
An NIH-funded study led by researchers at the University of Wisconsin-Madison and the University of Southern California found that a UK law keeping students in school one more year reduced dementia incidence decades later.
Researchers report that a 1972 education reform in the United Kingdom, which raised the minimum school-leaving age by one year, reduced the incidence of Alzheimer's disease and related dementias up to 50 years afterward. The work was funded by the National Institutes of Health and led by teams at the University of Wisconsin-Madison and the University of Southern California, Los Angeles.
Higher education has long been linked to lower dementia risk, but scientists have struggled to show that the link is causal. Answering that would require following a large group of students, some affected by an intervention and some not, for many years. The UK law, enacted in England, Wales and Scotland, created that kind of comparison. It raised the minimum dropout age from 15 to 16 for students born after Sept. 1, 1957, and enrollment through age 16 rose by 14%.
To measure long-term effects, the authors analyzed medical data from more than 100,000 participants in the UK Biobank, a large aging cohort. Diagnoses made before December 2022, when the oldest participants turned 65, served as the main comparison between people affected and unaffected by the reform. The researchers drew diagnoses from medical histories, hospital records and death registries, which they said limited biases that favor people who lived long enough to be diagnosed.
The additional year of school reduced incidence of Alzheimer's disease and related dementias over the following 50 years by 0.88%, which the release describes as a considerable effect because overall dementia rates in the study population were low. The effect was strongest among participants who carried genetic variants known to raise risk. The reform was also tied to improvements in socioeconomic factors and other areas of health, which may point to ways education reduces risk.
The authors urged caution because participant age was capped at 65. As the cohort ages and diagnoses become more common, differences between the groups could grow or shrink. Lead author Silvia Barcellos, a health economist at the University of Wisconsin-Madison, said: "There are few preventative options out there so even one could make a world of difference." The findings appear in the Proceedings of the National Academy of Sciences.
At a Glance
- The UK reform raised the minimum school dropout age from 15 to 16 for students born after Sept. 1, 1957.
- School enrollment until age 16 rose by 14% after the change.
- Researchers analyzed data from more than 100,000 UK Biobank participants.
- The extra year of school reduced dementia incidence over 50 years by 0.88%.
- The effect was strongest in people with genetic variants that raise Alzheimer's risk.
Sources
This brief was written by Brightside Report from the reporting linked above. Spot an error? Request a correction.