Loneliness linked to brain shrinkage and dementia, new study finds

As we get older, looking after our bodies becomes even more important in order to stave off some conditions and retain mobility.

However, keeping our brains active is just as crucial, with conditions such as dementia a growing problem among ageing populations.

Now a study has found one key factor in keeping the brain healthy – social interaction.

New research, published in Neurology journal, found that older people who have little social contact with others are more likely to have loss of overall brain volume than people with more frequent social contact.

This can also put them at greater risk for developing dementia, researchers said.

While the study does not prove that social isolation causes brain shrinkage; it only shows an association.

Study author Toshiharu Ninomiya, of Kyushu University in Fukuoka in Japan, explained: “Social isolation is a growing problem for older adults.

“These results suggest that providing support for people to help them start and maintain their connections to others may be beneficial for preventing brain atrophy and the development of dementia.”

As part of the study, 8,896 people with an average age of 73 who did not have dementia underwent MRI brain scans and health examinations.

They were also surveyed to understand how much social contact they experience and asked the question, “How often are you in contact with relatives or friends who do not live with you (either in person or on the phone)?”

The answers were categorised as “every day”, “several times a week”, “several times a month” and “seldom”.

Those who reported the lowest amount of social contact had overall brain volume that was significantly lower than those with the most social contact.

Total brain volume was 67.3 percent in the lowest contact group compared to 67.8 percent in the highest contact group.

These participants also had lower volumes in areas of the brain such as the hippocampus and amygdala, which play a role in memory and are affected by dementia.

Researchers accounted for other factors that could affect brain volume, including age, diabetes, smoking and exercise when compiling the results..

Symptoms of depression were also linked to brain size, and partly explained the relationship between social isolation and brain volumes.

But symptoms of depression accounted for only 15 percent to 29 percent of the association.

Ninomiya added: “While this study is a snapshot in time and does not determine that social isolation causes brain atrophy, some studies have shown that exposing older people to socially stimulating groups stopped or even reversed declines in brain volume and improved thinking and memory skills, so it’s possible that interventions to improve people’s social isolation could prevent brain volume loss and the dementia that often follows.”

Researchers acknowledged that their findings were limited by the fact that only older Japanese people were included in the study.

It comes as Age UK revealed around one million people aged over 75 said they can go over a month without speaking to a friend, relative or neighbour.

And more than two million people aged over 75 in England live alone.