Image of James B. Rowe; Image credit: University of Cambridge
James B. Rowe; Image credit: University of Cambridge

Reduced cognitive function without substantial memory complaints may be a normal part of aging and not an early sign of Alzheimer’s disease or other dementias, a new study has found. 

Investigators compared the brains of older adults who fit the description of “cognitively frail” with those of adults with a mild cognitive impairment (MCI), Alzheimer’s disease and healthy controls. Although the cognitively frail adults had similar functional measures as their peers with MCI, their brain activity and structure matched that of the healthy controls, according to James B. Rowe, Ph.D., of the University of Cambridge, United Kingdom.

Regions like the hippocampus that are typically atrophied in adults in Alzheimer’s were not compromised in the cognitively frail adults, Rowe and his colleagues reported. Taken together, the results suggest that poor cognition may simply be part of the “spectrum of cognitive aging,” they theorized.

In addition, lifestyle habits may contribute to loss of ability rather than the brain changes normally found in dementia, they wrote.

“Lower lifelong cognitive reserve, hearing impairment and cardiovascular comorbidities might contribute to the etiology of the cognitive frailty. Critically, community-based cohorts of older adults with low cognitive performance should not be interpreted as representing undiagnosed Alzheimer’s disease,” they concluded.

Full findings were published in the Journal of Neuroscience.