Dementia: an extra year of school lowers risk decades later, study finds

More education in youth may lower the risk of dementia in later life, a new study suggests. Researchers led by health economist Silvia Barcellos of the University of Wisconsin–Madison and the USC Schaeffer Institute used a school reform in England, Scotland and Wales: in 1972 the minimum school-leaving age was raised from 15 to 16. Those born on or after 1 September 1957 had to stay an extra year. The study appeared in the journal PNAS; the US National Institutes of Health (NIH) presented it on 23 October.

The researchers analysed data from more than 100,000 UK Biobank participants, including hospital records, death registries and medical histories up to age 65. The reform raised the share of people staying in school until 16 by 14 percentage points. People born shortly after the cut-off were less often diagnosed with Alzheimer's disease or a related dementia than those born shortly before it. The effect was strongest among people carrying genetic variants that raise Alzheimer's risk. Household incomes also rose, and strokes and heart attacks became less common.

'Our findings provide evidence that education itself can reduce dementia risk decades later,' Barcellos said, according to USC. Richard Hodes, director of the US National Institute on Aging, said according to the NIH that changes such as additional schooling can offset inherited vulnerability. The authors note limitations: because participants were at most 65 and dementia is still uncommon at that age, the estimates are imprecise. The mechanisms remain unclear, and further follow-up is needed to see whether the effect grows or shrinks with age.