Mental tasks take an extra effort for healthy non-demented older adults with a genetic variation called APOE-e4, which has been linked to an increased risk of developing Alzheimer’s disease, research shows.

On tests of learning and memory, brain scans show that people with APOE-e4 apparently have to work harder to achieve scores comparable to those reached by people with the APOE-e3 variant.
“This study confirms alterations in brain activity during learning in healthy older people at genetic risk for Alzheimer’s disease,” Dr. Mark W. Bondi from the VA San Diego Healthcare System told AMN Health.

Bondi and his colleagues had 20 non-demented adults (average age, 76) with normal learning and memory capabilities complete a picture-encoding task while undergoing magnetic resonance imaging.

In multiple brain regions, the 10 people with the APOE-e4 gene displayed greater intensity and extent of brain activation while learning new pictures, compared with the 10 individuals with the APOE-e3 allele.

The APOE-e4 group also displayed lower brain responses in another area during tasks of learning and memory, the researchers report in the journal Neurology.

“The implications of this finding,” Bondi told AMN Health, “include the possibility of providing new methods for identifying the earliest stages of Alzheimer’s disease.”

Tests based these findings may “help us recognize brain changes early so that we can identify the people at highest risk for the disease, with the goal of providing them with treatment more quickly and efficiently,” he added.

SOURCE: Neurology, February 8, 2005.