Vitamin D deficiency linked to early Alzheimer‑related brain changes; multilingualism linked to younger brain age

A study of participants from the Framingham Heart Study, whose average age was 39 at the time of blood testing, found that lower vitamin D levels in mid‑life were associated with greater accumulation of tau protein in brain regions vulnerable to Alzheimer’s disease 16 years later. The researchers reported that vitamin D status did not correlate with amyloid plaques, suggesting an early effect on tau pathology. Lead author Martin Mulligan of the University of Galway said, “Addressing a vitamin D deficiency in mid‑life is particularly important, because you can intervene before memory loss or dementia symptoms appear.”

Separate research presented at a neuroscience conference in Barcelona analyzed 850 brain scans of adults from the multilingual Basque region of northern Spain. The investigators observed that the estimated brain age of participants who spoke two languages was up to six years younger than monolinguals, three languages corresponded to a seven‑year reduction, and four languages to as much as 13 years younger brain age. The effect was strongest for individuals who had been bilingual or multilingual from early childhood. These findings suggest that sustained language use may slow brain aging, potentially lowering dementia risk.