A British schooling reform from 1972 appears to have reduced dementia diagnoses decades later, with new analysis showing an extra year of compulsory education lowered the risk even among those carrying a strong inherited predisposition to the condition.
Dementia encompasses a range of neurodegenerative disorders marked by memory loss and declining cognitive function, with Alzheimer’s disease accounting for many cases. As life expectancy climbs, health researchers have pressed for modifiable life experiences that could delay or prevent the onset of dementia.
Education has long been studied as a potential factor, though evidence has been mixed. A 2011 systematic review found higher dementia risk among people with less schooling in about half of the populations studied, yet observational research struggles to separate the effect of education from childhood poverty, health, or inherited traits. Earlier analyses suggested higher education correlated with better baseline memory and larger brain size but did not prove a slower rate of normal age-related decline or to translate into fewer dementia diagnoses.
The new study, led by Silvia Helena Barcellos of the University of Wisconsin–Madison, uses a natural experiment created by the 1972 Raising of School-Leaving Age Act, which lifted the minimum leaving age from 15 to 16 in England, Scotland and Wales. The researchers employed a regression discontinuity design, comparing people born just before and just after the September 1, 1957 cutoff, with similar genetic risk profiles and parental dementia rates, to isolate the causal effect of extended schooling.
Participants were drawn from the UK Biobank, a large health study of more than half a million British adults aged 40 to 69 when recruited. Rather than relying on follow-up surveys alone, the team tracked dementia diagnoses through December 2022 using linked hospital records, death registries and medical histories. Validation testing in this database indicates that at least 84.5 per cent of dementia cases identified through administrative records are true positives.
In the genetic analyses, the researchers used a polygenic index that combines many common DNA variants with the APOE gene, known for its strong link to Alzheimer’s risk. Across the high and low genetic risk groups, the APOE4 variant was present in 58 per cent of high-risk individuals and in 0.02 per cent of the low-risk group.
The reform raised the share of pupils staying in school until 16 by 14 percentage points and added an average of 0.19 years of schooling. By December 2022, the first affected cohort had reached age 65, and 0.49 per cent of those born before the cutoff had a dementia diagnosis. Those born under the reform were 0.20 percentage points less likely to have a dementia diagnosis, with similar trends for men and women.
When the authors extrapolated to a full additional year of schooling for those who left school at 18 or younger, they estimated a 0.88 percentage point reduction in dementia incidence. Given the cohort’s age, dementia remained relatively uncommon at the time, and the authors acknowledged substantial sampling variation in the estimate, with a 95 per cent confidence interval from 0.15 to 1.76 percentage points. They cautioned that the exact magnitude is uncertain, but the direction of the effect is informative.
“One of the most striking findings was that education appeared to weaken the relationship between genetic predisposition and dementia,” Barcellos explained. “People with higher genetic risk seemed to benefit particularly strongly from the additional schooling. This is especially interesting because genetic risk is often thought of as something fixed. While we cannot change the genes we inherit, our findings suggest that the consequences of those genes can be influenced by our environments and experiences.”
She added: “I think this is a hopeful message: our genes do not necessarily determine our destiny. Even for diseases like Alzheimer’s, where genetics can play an important role, experiences and circumstances that can be changed, such as education, may influence whether someone develops the disease.”
The study also connects with earlier work suggesting lifelong learning can bolster cognitive ability, though the prior evidence examined short-term gains in older adults rather than long-term dementia outcomes decades later. The authors note that staying in school until 16 may also influence later-life health behaviours and economic conditions, which in turn could affect brain health.
To explore possible pathways, the researchers looked at midlife outcomes. Those born under the reform were 2.3 percentage points more likely to have an annual household income of at least £31,000 and 0.64 percentage points less likely to have suffered a stroke or heart attack, with the cardiovascular benefit concentrated among the high genetic risk group. Reductions in diabetes and obesity were not statistically significant, and those affected by the reform were more likely to develop stage 1 high blood pressure.
The authors emphasise several caveats. The first cohort affected by the 1972 reform had reached only 65 by the end of the study, and dementia remains rare at that age, leading to wide margins of error. Sweden’s experience with a similar policy found no effect on dementia, underscoring that results may depend on country context and the particular features of the reform. The study focuses on basic secondary education for students who would otherwise have left school early and does not extend to outcomes from longer cycles of higher education.
Limitations aside, the researchers propose that educational policy may influence not only economic opportunities but health trajectories and disease risk if implemented early in life. They are widening the inquiry to Finland and the Netherlands to assess cross-country consistency and aim to uncover the mechanisms behind the observed effects—whether through income, health behaviours, cardiovascular risk, or other pathways.
“Education policies implemented early in life may have consequences that extend many decades into the future,” Barcellos concluded. “The study also illustrates how social policies can help us understand and potentially reduce health risks that are often considered largely biological or genetic.”
The study, “Education reduces dementia incidence and mitigates genetic risk,” is authored by Silvia H. Barcellos, Leandro S. Carvalho, Kenneth M. Langa, Sneha Nimmagadda, and Patrick Turley.
