A groundbreaking new study has revealed that Alzheimer's disease is significantly more prevalent among the very elderly than previous estimates suggested. The research, which analysed thousands of blood samples, also indicates that a simple blood test could be key to detecting the condition in its earliest, symptom-free stages.
Key Findings on Alzheimer's Prevalence
The unique research project, a collaboration between King's College London, Stavanger University Hospital, and the University of Gothenburg, examined 11,486 blood samples from individuals in Norway aged 57 and over. Scientists searched for specific proteins in the blood linked to cognitive decline.
The results were striking. The study found that Alzheimer's disease neuropathological changes (ADNC) were present in fewer than 8% of people aged 65 to 69. However, this figure rose dramatically to 65.2% in patients over the age of 90, indicating the condition is far more widespread in the oldest populations than previously understood.
The Promise of Early Detection
Critically, the analysis showed that over 10% of people aged 70 and above had pre-clinical Alzheimer's, a stage with no visible symptoms. A further 9.8% were found to have Alzheimer's dementia. This means more than one in ten individuals over 70 could meet the criteria for new drugs designed to slow the disease's early progression.
Professor Dag Aarsland of King's College London emphasised the importance of the findings. "It is vital that we are able to detect signs of dementia at the earliest possible stages," he said. "This blood test looks to be an effective means of providing that clarity at scale."
Education Link and Research Impact
The research also uncovered a notable correlation between education levels and Alzheimer's pathology. The study concluded that ADNC 'was more prevalent in individuals with lower education', adding another layer to our understanding of the disease's risk factors.
Dr Richard Oakley from the Alzheimer's Society highlighted the scale of the data. "This is the first time we've seen this type of data from such a large group of people," he stated, underscoring the study's significance for future dementia research and public health strategy.
The findings pave the way for wider use of blood-based biomarkers in screening, potentially revolutionising how we approach early detection and intervention for Alzheimer's, the most common cause of dementia.
