Social isolation increases the risk of developing dementia
A new study has shown that loneliness can reduce brain size and increase the risk of developing dementia. Scientists from Japan studied MRI images of 8896 people aged 65 years and older. It turned out that people with the lowest level of social contacts have a significantly smaller brain size.
Social isolation in the elderly can lead to a decrease in brain volume, writes the Daily Mail. It was previously thought that a lack of social contact and the lack of brain stimulation that comes from talking lead to dementia.
The researchers wanted to understand how isolation affects the brain, so they examined 8,896 people aged 65 years and older who underwent MRI scans.
Volunteers participating in the study were asked how often they had contact with relatives and friends who did not live with them, such as dating or talking on the phone. Participants could choose an answer every day, several times a week, several times a month, or rarely.
The people with the lowest levels of social contact had a significantly smaller brain volume compared to those with the most social contact.
Their total brain volume, which is the sum of white and gray matter, as a percentage of their total brain volume skull, was 67.3% in the lowest contact group compared to 67.8% in the highest contact group. They also had smaller brain volume in areas of the brain including the hippocampus and amygdala, which play an important role in memory and are associated with dementia.
The hippocampus is one of the first areas affected by Alzheimer's disease, explains the Daily Mail.
Perhaps the lack of social contact hastens the gradual shrinkage of the brain that occurs as people age. However, isolated people also tend to lead more unhealthy lifestyles, which can be harmful to their brains.
Dr. Toshiharu Ninomiya, senior author of the study at Kyushu University in Japan, notes: “Social isolation is a growing problem for older people. These results suggest that providing support to people who help them establish and maintain their connections with others may be beneficial in preventing brain atrophy and dementia.»
It was found that the relationship between the lack of social contacts and the smaller brain size found in older Japanese is the case even after controlling for other factors that can affect the brain, including a person's weight, smoking and drinking habits, and whether they have diabetes.
But a study published in the journal Neurology notes that people who lose brain volume may experience personality changes, such as becoming more lethargic. This may cause them to see people less often, rather than more frequent human encounters causing brain changes.
Socially isolated people in the study also had more small areas of damage in the brain called white matter lesions than people with frequent social contact.
The proportion of intracranial volume formed by white matter lesions was 0.30% in the socially isolated group compared to 0.26% in the most socially connected group, writes the Daily Mail.
Researchers have found that depression, which is associated with brain shrinkage, partly explains the relationship between social isolation and brain volume.
However, symptoms of depression explained only a small part of this result.
Dr. Isolation causes brain atrophy, some studies have shown that older people's exposure to socially stimulating groups halted or even reversed brain volume decline and improved thinking and memory skills. So it is possible that interventions to improve the condition of people could prevent the loss of brain volume and the dementia that often follows.