Alzheimer's research identifies age-50 brain changes and new prevention trials

Researchers have identified significant changes in the brain occurring around age 50 that may contribute to neurodegenerative diseases. A study involving the University of California, San Diego, the University of California, Irvine, and the New York Genome Center found that around this age, resident immune cells known as microglia are increasingly replaced by immune cells entering from the bloodstream. These new cells carry stronger inflammatory signals, which may drive chronic inflammation linked to cognitive decline and Alzheimer's disease.

In parallel, a large-scale international clinical trial named PrevenTRON is testing whether the drug trontinemab, developed by Roche, can prevent dementia in asymptomatic individuals. The trial, involving approximately 1,600 participants aged 55 to 80, utilizes the p-tau217 blood biomarker to identify those at high risk of cognitive impairment. Trontinemab works by targeting amyloid plaques, toxic proteins that accumulate in the brain. Early research suggests the drug can clear these plaques in a majority of patients with early-stage Alzheimer's.