In a landmark study that provides the clearest real-world picture to date, researchers have discovered that one in ten people in the UK aged 70 and older show brain changes associated with Alzheimer's disease. The findings, published on 17 December in the prestigious journal Nature, indicate that more than 1 million individuals could meet the clinical criteria for new anti-amyloid drug therapies.
A Game-Changer in Dementia Understanding
This first-ever population-based research, conducted by a team from King’s College London, Stavanger University Hospital, and the University of Gothenburg, moves beyond small clinical samples. By analysing blood biomarker data from a random sample of nearly 11,500 people, it offers unprecedented insight into how common these protein changes are in the general ageing population.
The study's lead author, Professor Dag Aarsland of King’s College London's Institute of Psychiatry, Psychology and Neuroscience, described the work as a potential "gamechanger" in comprehending the disease. "In an ageing global population, the assessment and treatment of dementia presents a significant challenge," Aarsland stated. The research utilised a simple p-tau217 blood test, recently cleared by regulators, which can identify Alzheimer's pathology much earlier than previously possible.
Stark Contrast to Current NHS Capacity
The scale revealed by the study presents a significant challenge for the National Health Service. While over a million over-70s may qualify for treatment based on Nice's criteria, the NHS has estimated it could only fund such therapies for around 70,000 people if resources were available. This stark gap highlights a pressing healthcare dilemma.
David Thomas, Head of Policy at Alzheimer’s Research UK, emphasised the importance of the findings for future diagnostics: "High-quality studies like this are crucial to enhancing our understanding of how blood tests for Alzheimer’s could be used in clinical practice. We need to generate more evidence so we can use these tests in the NHS."
New Insights and Future Directions
The research also challenges some long-held assumptions, including the notion that dementia predominantly affects women. It provides the first direct, age-related prevalence data:
- Fewer than 8% of people in their 50s and 60s carry the marker.
- Just over a third of those in their 70s.
- About two-thirds of people over 90.
It is crucial to note that the detection of these proteins is not a diagnosis of dementia. The study measures current brain changes and does not predict who will develop clinical symptoms—a key area for Professor Aarsland's future research. He also aims to explore how these tests, currently unavailable on the NHS, could be integrated into primary care via GPs.
Professor Tara Spires-Jones from the University of Edinburgh called the data "very interesting, strong, and accurate," noting that while current anti-amyloid treatments are expensive and risky, improving therapies will make accessible testing vital. Professor Eric Brunner of UCL added that the research signals a new era where we are no longer "powerless to treat" dementia, but the sheer numbers underscore that the NHS cannot afford to treat all potential beneficiaries at current costs.
With nearly 1 million people currently living with dementia in the UK—a figure projected to rise to 1.4 million by 2040—this study underscores the urgent need for scalable diagnostic tools and cost-effective treatments to address the coming wave of age-related cognitive decline.
