Around one in 10 people in the UK aged 70 and over may have brain changes associated with Alzheimer’s disease, according to the largest population-based study to date examining how common these changes are in older adults.
The findings do not amount to a diagnosis of Alzheimer’s, but they suggest that more than 1 million people could meet current NHS clinical criteria for treatment with anti-amyloid drugs. This is far higher than previous NHS estimates of about 70,000 potential patients.
The study, published in Nature on 17 December, analysed blood samples from nearly 11,500 randomly selected people using a p-tau217 blood test, a biomarker that can detect Alzheimer’s-related changes earlier than previous methods. About 10% of those aged 70 and above showed evidence of amyloid-related brain changes.
Researchers say the results provide the clearest real-world picture yet of how widespread these changes are and could transform early detection. Professor Dag Aarsland of King’s College London, the study’s lead author, described the findings as a potential “gamechanger” for understanding Alzheimer’s and identifying people before symptoms develop.
The prevalence of the biomarker increased sharply with age: fewer than 8% of people in their 50s and 60s carried it, just over a third of those in their 70s, and around two-thirds of people aged over 90.
Experts welcomed the findings but warned of major implications for healthcare systems. While early detection could improve future treatment, current anti-amyloid drugs are costly and not routinely available on the NHS. Researchers stress that reducing costs and risks, alongside further evidence, will be crucial before widespread screening and treatment can be introduced.
Nearly 1 million people currently live with dementia in the UK, a figure expected to rise to about 1.4 million by 2040.
