Can a Simple Blood Test Predict Alzheimer’s Years Before Symptoms?

Alzheimer’s disease does not start the day someone forgets a name. It develops slowly and silently in the brain for years, sometimes even decades, before symptoms show up. By the time memory problems begin, damage has already been building for a long time. A new study published in nature medicine looked at whether a simple blood test could help predict when symptoms might start. The researchers focused on a blood marker called plasma p-tau217 and created what they call “p-tau217 clocks” to estimate how close someone may be to developing symptoms.