A comprehensive and unique study has unveiled new insights into the prevalence of Alzheimer's disease, suggesting that it is more widespread in individuals over the age of 85 than previously understood. The research also indicates that over one in ten people above 70 years old would meet the criteria for drugs designed to slow the early stages of the disease.

Conducted by researchers from King's College London, Stavanger University Hospital, and the University of Gothenburg, the study involved the analysis of 11,486 blood samples from Norwegian residents over the age of 57. The focus was on detecting the frequency of specific proteins in the blood that are linked to cognitive impairment. While the study found these proteins to be more prevalent in older age groups, their presence was lower than earlier estimates in younger demographics.

Key findings revealed that Alzheimer's disease neuropathological changes (ADNC) were more prevalent in individuals with lower educational backgrounds. The prevalence of ADNC was less than 8 percent in those aged 65 to 69, but significantly increased to 65.2 percent in patients over 90. Furthermore, among individuals over 70, the study identified that 10 percent had pre-clinical Alzheimer's, a stage characterized by no overt symptoms, while 9.8 percent were diagnosed with Alzheimer's dementia.

Professor Dag Aarsland from King's College London emphasized the importance of early detection, stating, 'It is vital that we are able to detect signs of dementia at the earliest possible stages. This blood test looks to be an effective means of providing that clarity at scale.' Dr. Richard Oakley of the Alzheimer's Society underscored the novelty of the data, noting, 'This is the first time we've seen this type of data from such a large group of people.'