A new discovery shows that the severity of amyloid deposition in the brain may determine who benefits from anti-amyloid therapies for Alzheimer's disease.
Scientists found that the buildup of toxic amyloid beta clumps, which are associated with Alzheimer's, accelerates as people get older.
However, the amount of amyloid present in the brain and overall brain health before this acceleration were better indicators of who would develop Alzheimer's.
How it was discovered
The study wanted to find better ways to treat dementia by understanding how amyloid builds up in the brains of people without memory problems.
Amyloid clumps are common in Alzheimer's, but most studies only looked at younger people, so we didn't know how amyloid relates to dementia in older adults.
The researchers studied 95 older adults who were not experiencing memory problems at the beginning of the study.
They followed them for 11 years or until they passed away.
They compared how amyloid built up in their brains with a group of younger people from another study.
They discovered that amyloid increased in everyone's brains over time, but it happened faster in those who were 80 years old or older.
That's why amyloid is more common in very old people.
Only a small number of participants developed dementia if they didn't have amyloid in their brains.
Those who had amyloid at the start of the study developed dementia two years earlier than those without amyloid.
Why it's important
Understanding the timing of these pathologies is crucial for future prevention therapies.
The researchers couldn't examine whether there is a vascular process occurring alongside amyloid deposition in this study, but it will be important to consider in future treatments.
Previously, we talked about brain cells tied to surprise.
