Groundbreaking new research has provided the first clear, population-level snapshot of how common Alzheimer's disease-related brain changes are among older people in the UK. The findings suggest a significant portion of the elderly population may be living with underlying biological markers of the condition.
Real-World Data Reveals Startling Prevalence
The study, published on 17 December in the prestigious journal Nature, indicates that one in ten people aged 70 and older in the UK could have Alzheimer's-like protein changes in their brain. This is the first research of its kind to move beyond small clinical samples, instead using blood biomarker data from a randomly selected group of nearly 11,500 individuals.
Led by experts from King’s College London, Stavanger University Hospital, and the University of Gothenburg, the work offers a stark real-world picture. It found that while fewer than 8% of people in their 50s and 60s carry the marker, this rises to just over a third of those in their 70s, and about two-thirds of people over the age of 90.
A Potential 'Gamechanger' for Diagnosis and Treatment
The research utilised a p-tau217 blood test, recently cleared by regulators, which can identify Alzheimer's pathology much earlier than previously possible. Professor Dag Aarsland, the study's lead author from King’s College London, described the findings as a potential "gamechanger in the understanding of the disease."
Critically, the detection of these proteins is not a diagnosis of dementia, and the study only measures current brain changes, not who will develop clinical symptoms. However, it means that over 1 million people over 70 in the UK would meet the NHS clinical criteria for anti-amyloid therapy. This figure starkly contrasts with the NHS's own estimate that only 70,000 people could be eligible if funding were available.
David Thomas, Head of Policy at Alzheimer’s Research UK, emphasised the importance of the study: "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."
Challenges and Hope for the Future
The sheer scale of potential eligibility highlights a major challenge for the healthcare system. Professor Eric Brunner of University College London noted that while the research shows we are "entering a new era when dementia is no longer something where we’re powerless to treat," the NHS "can in no way afford to treat all those who could benefit at the current cost."
Professor Tara Spires-Jones from the University of Edinburgh echoed this, pointing out that while current treatments are expensive and risky, "as these get better over the next few years it’s important that we can find people with amyloid in their brain using an easy test."
The findings also challenge some long-held assumptions, including the idea that dementia predominantly affects women. Professor Aarsland stated his next steps will involve researching who will go on to develop dementia and working with GPs to explore how these tests could be integrated into primary care, where they are not currently available on the NHS.
With nearly 1 million people currently living with dementia in the UK—a number projected to rise to 1.4 million by 2040—this research underscores the urgent need for scalable, affordable diagnostic tools and treatments to address a looming public health challenge.
