Cognitive Decline is Not Always Due to Alzheimer’s, Researchers Say
When we notice cognitive issues in ourselves or loved ones, it may lead to worry about Alzheimer’s. However, a new study finds that often, it can just be a byproduct of aging.
Researchers from the University of Cambridge examined the brains of healthy seniors and those with different cognitive issues. They found that the brains of participants who were cognitively frail – defined as having reduced cognitive function but no noticeable memory issues – had a closer resemblance to those of the healthy control group rather than the Alzheimer’s group. The findings were published in the journal JNeurosci.
The study says, “Our results call for caution before assuming that cognitive frailty represents latent Alzheimer’s disease. Instead, the cognitive underperformance of cognitively frail adults could result in cumulative effects of multiple psychosocial risk factors over the lifespan, and medical comorbidities.”
To conduct their research, the team recruited participants from the Cambridge Centre for Ageing and Neuroscience study. The study included healthy adults, as well as those with a mild cognitive impairment (MCI), Alzheimer’s disease, or cognitive frailty. Participants underwent cognitive tests, had their brain structure analyzed via MRI, and had their brain activity gauged with EEG and MEG.
Though cognitively frail adults performed similarly to those with MCI on the cognitive tests, their brain activity and structure were closer to those of the healthy participants. They didn’t display atrophy in the hippocampus, which is regularly seen in adults with Alzheimer’s.
The study says, “Our results suggest that community-based cognitively frail represents a spectrum of normal aging rather than incipient Alzheimer’s disease, despite similar cognitive function. Lower lifelong cognitive reserve, hearing impairment, and cardiovascular comorbidities might contribute to the etiology of the cognitive frailty.”
The team notes that other contributing factors to cognitive frailty may include physical activity, stress, and education.
The researchers say the takeaway is that it may not be wise to assume that groups of older adults with low cognitive performance are a sign of undiagnosed Alzheimer’s.
