Brain imaging shows lifetime cognitive activity may influence Alzheimer's disease risk
Deposits of amyloid protein in the brain are considered a hallmark of Alzheimer’s disease. Now, for the first time, greater levels of cognitive activity—reading, writing, and playing games—have been associated with lower amyloid levels in the brains of cognitively healthy older people, according to NIA-supported research published online January 23 in the Archives of Neurology.
Researchers at the University of California, Berkeley imaged the brains of 65 cognitively normal volunteers aged 60 and older using positron emission tomography (PET) and Pittsburgh Compound B (PiB), a tracer that binds to amyloid in the brain. The participants provided estimates of the frequency of their cognitive activities over their lifetimes and underwent neuropsychological testing of their memory and other cognitive functions. The researchers then compared the brain scans of these healthy older participants to brain scans of 10 volunteers with Alzheimer’s disease and to 11 cognitively healthy volunteers in their 20s.
The researchers found a significant association between higher levels of mental stimulation over a lifetime and lower levels of amyloid in the brains of the healthy older volunteers. The relationship remained significant even when accounting for age, gender, and years of education. Other lifetime activities examined, such as current levels of cognitive activity, did not show an association with amyloid deposits. The results may suggest frequent engagement in cognitive activity in early and mid-life might help to delay or prevent the abnormal levels of amyloid in the brain, which accompany Alzheimer’s disease in later life. The NIA and the Alzheimer’s Association funded the study.
Landau, S.M., et al. Association of lifetime cognitive engagement and low B-amyloid deposition. Archives of Neurology. Published online Jan. 23, 2012.