New research published in the Annals of Neurology suggests that the brain’s ability to clear away a toxic protein fragment called amyloid beta 42, which is linked to Alzheimer’s disease, is reduced in older people.
The study’s senior author, Randall J. Bateman,  notes “We found that people in their 30s typically take about four hours to clear half the amyloid beta 42 from the brain. In this new study, we show that at over 80-years-old, it takes more than 10 hours.â€
Study researchers from Washington University in St. Louis tested a total of 100 volunteers between the ages of 60 and 87. Half the participants showed clinical signs of Alzheimer’s disease, which included memory problems, and 62 participants had plaques forming in their brains. The team then used a specific technology called SILK (stable isotope-linked kinetics) so they could observe what happened to the amyloid beta 42 and other proteins.
For participants who had evidence of plaques—researchers discovered that amyloid beta 42 was more likely to drop out of the fluid that bathes the brain and accumulate into plaques.
Researchers also discovered that lower rates of amyloid beta 42 clearance (i.e. found in older participants) were linked to symptoms of Alzheimer’s disease, including memory impairment and dementia.
Scientists agree that the brain has four different ways of clearing amyloid beta: moving it to the spine, driving it through the blood–brain barrier (BBB), disbanding it with other proteins, or depositing it as plaques.
Bateman hopes the team can identify which of the first three channels for amyloid beta clearance slows down as the brain ages, as it could be beneficial in developing new treatments.
Source for Today’s Article:
Paddock, C., “Clearance of Alzheimer’s protein in brain reduces with age,†Medical News Today web site, August 7, 2015; http://www.medicalnewstoday.com/articles/297871.php.