‘Social isolation contributes to human brain atrophy and cognitive decline,’ study finds
Social isolation contributes to brain atrophy and cognitive decline, suggesting that there’s an opportunity to reduce dementia by promoting social bonds, according to a new study published in eLife.
According to the study, researchers said they found changes in the brain associated with social isolation. Also, poorer cognitive functions (memory, processing speed, executive functions) were linked to greater social isolation.
More than 50 million people suffer from dementia worldwide. In just 20 years, this number is expected to double. Currently, dementia’s global annual costs exceed $1 trillion, researchers said.
As many as 3.5% of dementia cases could be attributed to social isolation, the study said. This is almost as many as obesity, hypertension, and diabetes combined, the study explained.
“Research on pharmacological interventions targeting dementia pathogenesis has not yielded any result with a clear clinical benefit yet, and available drugs targeting cognitive symptoms offer at most a minor alleviation,” the study said. “Prevention is of cardinal importance and potentially modifiable risk factors are our most promising target.”
On Thursday, the U.S. Food and Drug Administration granted full approval to the Biogen and Eisai Co. Ltd. Alzheimer’s treatment Leqembi, the first drug shown to slow the progress of the disease. Leqembi, also known as lecanemab, is a monoclonal antibody designed to reduce the buildup of amyloid beta plaque in the brain, a marker of Alzheimer’s disease.
To investigate the effects of social isolation on brain structure and cognitive performance, the study examined 1,335 cognitively healthy participants and followed up with 912 participants after six years.
“We provide evidence that social isolation contributes to human brain atrophy and cognitive decline…. indicating an opportunity to reduce dementia risk by promoting social networks,” researchers said in the study.
Changes in the brain related to dementia include vascular degeneration, amyloid plaques, tau fibrillary tangles, neural degeneration, and gray matter loss. These brain changes have been observed years prior to symptoms emerging and can be detected using neuroimaging.
As a result, brain magnetic resonance imaging (MRI) might offer crucial guidance to identify patients for intensive dementia prevention, the study said.