- Researchers have found an association between social isolation and lower brain volume.
- A loss of brain volume suggests neurodegeneration that may result in dementia or Alzheimer’s disease.
- While establishing a causal link between social isolation and brain-volume loss was beyond the scope of this study, other research supports this possibility.
- In addition, previous studies have linked social isolation to cognitive loss and dementia.
A new study finds an association between social isolation and a reduction in brain volume among older people. Brain volume loss is considered a sign of neurodegeneration due to cell death and atrophy.
Among the study’s participants, MRI scans showed that the white and gray brain matter of those with the least social contact occupied 67.3% of the available intracranial volume. Those with the highest amount of social contact occupied 67.8%.
The correspondence between social isolation and dementia does not indicate that one causes the other. However, it may offer a clue as to what causes dementia.
The results of this study appear in Neurology.
The researchers — from Kyushu University in Fukuoka, Japan — found that a reduction in brain volume affected areas linked to memory and dementia, such as the hippocampus and amygdala. The hippocampus is a brain region believed to be associated with Alzheimer’s disease.
The temporal lobe, occipital lobe, and cingulum were also reduced. The researchers found that depression was a contributing factor but only accounted for 15% to 29% of the connection between social isolation and brain volumes.
The scans also revealed that the most socially isolated people had a higher amount of white matter lesions that indicate brain damage.
White matter lesions constituted 0.30% of intracranial volume for those people and 0.26% for people who were not as socially isolated.
The study involved 8,896 dementia-free people with an average age of 73 living in a community setting in Japan.
Prof. Barbara Sahakian, a…
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