Scientists are scanning the brains of healthy elderly citizens as part of an ambitious new Alzheimer's treatment which hopes to discover the cause of the disease.
Previous research has identified two hallmarks of Alzheimer's - sticky brain plaque and tangles of a protein named tau that clog dying brain cells. Using the latest technology, experts can now spot these tangles in living brains - and they hope that extensive scanning of healthy subjects will provide clues to what triggers the debilitating disease.
The tau brain scans will be added to a new study in the U.S. that's testing if an experimental drug might help healthy but at-risk people stave off Alzheimer's.
Whether that medication works or not, it's the first drug study where scientists can track how both of Alzheimer's signature markers begin building up in older adults before memory ever slips. More than 35 million people worldwide have Alzheimer's or similar dementias, including about five million in the U.S. Those numbers are expected to rise rapidly as the baby boomers get older. There is no good treatment.
Today's medications only temporarily ease symptoms and attempts at new drugs, mostly targeted at sticky amyloid, have failed in recent years. Some believe treatment needs to start at an earlier stage.
Scientists now think Alzheimer's begins quietly ravaging the brain more than a decade before symptoms appear, much like heart disease is triggered by gradual cholesterol buildup.
Brain scans show many healthy older adults quietly harbour those sticky amyloid plaques, not a guarantee that they'll eventually get Alzheimer's but an increased risk.
Yet more recent research, including a large autopsy study from the Mayo Clinic, suggests that Alzheimer's other bad actor - that tangle-forming tau protein - also plays a big role.
