An ambitious study is testing to see if an experimental drug can help healthy but at-risk people stave off Alzheimer's. Scientists are scanning the brains of healthy elderly citizens as part of the study.
Previous research has identified two hallmarks of Alzheimer's: sticky brain plaque known as amyloid build-up, and tangles of a protein named tau that clog dying brain cells. The newest theory is that Amyloid sparks a smoldering risk, but a later spread of toxic tau speeds the brain's destruction.
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.
Participants in the study who are deemed at risk of developing the disease will be given either the new anti-amyloid drug or a placebo. 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.
Today's medications only temporarily ease symptoms and attempts at new drugs, mostly targeted at sticky amyloid, have failed in recent years. 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 build-up.
More than 35 million people worldwide have Alzheimer's or similar dementias, including about five million in the US. Those numbers are expected to rise rapidly as the baby boomers get older.