A number of studies have shown that high levels of amyloid beta protein in the brain is associated with Alzheimer's disease, but now researchers say that high levels of this plaque can hinder the mental performance of adults who do not have Alzheimer's.
The study, published in the online issue of Neurology, showed that adults who seemed to be in good cognitive health experience changes in memory and mental function when the amount of amyloid beta in their brains is increased.
Researchers looked at 137 healthy, educated people without dementia between the ages of 30 and 89. They were tested for the Alzheimer's gene, given brain scans and tests on working memory, reasoning and speed of processing information.
The study showed the amount beta-amyloid in the brain seems to increase with age, with about 20 percent of adults over age 60 showing significantly high levels of the plaque in their brains. Those with higher levels of beta amyloid scored lower on the cognitive function tests.
"A key question for future research is whether some adults with high levels of beta-amyloid will maintain good mental function for a long period of time and whether higher beta-amyloid deposits in healthy adults always predetermines cognitive decline," said study author Dr. Denise C. Park.