According to a study recently published in Neurology, the medical journal of the American Academy of Neurology, people in the older age group who have little social interaction may be more likely than those who interact with others frequently to experience a loss of overall brain volume, particularly in regions that are frequently affected by dementia.
It is significant to remember that the study did not establish a causal link between social isolation and brain shrinkage; rather, it only found a correlation between the two.
According to research author Toshiharu Ninomiya, MD, PhD, of Kyushu University in Fukuoka, Japan, “Social isolation is a growing problem for older adults.” These findings imply that assisting people in establishing and maintaining relationships with others may be helpful in halting brain deterioration and the onset of dementia.
The study included 8,896 healthy individuals with an average age of 73. They got physical examinations and MRI brain scans. People were asked one question to gauge social contact: How frequently do you meet or speak on the phone with family or friends who do not live with you? Everyday, many times per week, several times per month, and rarely were the options given as responses.
The overall brain volume was much lower in the participants with the least social contact than in the people with the most social contact. The total intracranial volume, or the volume inside the skull that includes the brain, meninges, and cerebrospinal fluid, was 67.8% in the highest contact group compared to 67.3% for the total brain volume, or the sum of the white and grey matter. Additionally, they exhibited smaller brain sizes in regions of the brain that are involved in memory and are impacted by dementia, such as the hippocampus and amygdala.
The researchers included additional elements including age, diabetes, smoking, and exercise that might have an impact on brain volume.
In addition, white matter lesions—small areas of damage in the brain—were more prevalent in the socially isolated individuals than in those with regular social contact. White matter lesions comprised up 0.30 of the cerebral volume in the group that was the least socially linked, as opposed to 0.26 in the group that was the most socially connected.
Researchers discovered that depressive symptoms contributed to the link between social isolation and brain volume. But only 15% to 29% of the association was due to depressive symptoms.
It’s possible that interventions to reduce social isolation could prevent brain volume loss and the dementia that frequently follows, according to Ninomiya. “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,” she said.
One drawback is that the results might not apply to younger people and persons of different races because the study only included older Japanese people.
Reference:
“Association Between Frequency of Social Contact and Brain Atrophy in Community-Dwelling Older People Without Dementia – The JPSC-AD Study” by Naoki Hirabayashi, Takanori Honda, Jun Hata, Yoshihiko Furuta, Mao Shibata, Tomoyuki Ohara, Yasuko Tatewaki, Yasuyuki Taki, Shigeyuki Nakaji, Tetsuya Maeda, Kenjiro Ono, Masaru Mimura, Kenji Nakashima, Jun-ichi Iga, Minoru Takebayashi and Toshiharu Ninomiya, 12 July 2023, Neurology.