A new study published in The Lancet found that Alzheimer's disease pathology can be detected in middle-aged adults — decades before dementia symptoms emerge. Researchers measured blood biomarkers in 1,350 dementia-free adults and found that 6% showed signs of Alzheimer's pathology. Those with positive biomarkers already performed worse on processing speed and executive function tests. Over five years, they faced more than double the risk of verbal memory decline and nearly four times the risk of processing speed decline. The findings suggest a critical window in midlife where early detection and intervention may slow or prevent dementia progression. Blood-based biomarkers offer a minimally invasive screening approach, though experts caution they should not be used as standalone diagnostic tools in the general population.
