An extra year of school, measured fifty years later, meant less dementia

In 1972, Britain raised the school leaving age from 15 to 16 — a natural experiment nobody designed for science. Researchers have now followed more than 100,000 UK Biobank participants and found that the extra year of schooling was followed, up to fifty years later, by measurably lower dementia incidence — with the strongest protection in people whose genes put them at highest risk. The NIH-funded study, led from the University of Wisconsin–Madison and USC, is among the strongest evidence yet that education does not just correlate with a healthier brain: it helps cause one. A policy about teenagers turned out to be a policy about grandmothers.

SDG 3 · Good health and well-being — Mechanism: policy reform