Maintaining friendships and other social connections may be vital for keeping your brain in shape as you age. A large new study suggests that older adults who are more isolated face a greater risk of brain shrinkage — especially in areas of the brain related to dementia — compared with those who have more frequent social interactions.
“Social isolation is a growing problem for older adults,” said study author Toshiharu Ninomiya, MD, PhD, of Kyushu University in Fukuoka, Japan, in a statement. “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.”
The analysis involved about 9,000 Japanese adults without dementia aged 65 and older. Around 57 percent were women, and the average age was 73. All participants underwent MRI scans and received a comprehensive health examination.
Dr. Ninomiya and collaborators determined each person’s frequency of social interactions by asking a single question: How often are you in contact with relatives or friends who do not live with you (e.g., meeting or talking with them on the phone)? The choices for answering were every day, several times a week, several times a month, or seldom.
Published July 12 in the journal Neurology, the findings showed that total brain volume (the sum of the gray and white matter) was 67.3 percent among those having the lowest contact compared with 67.8 percent in the group with the most contact. Those with fewer social interactions and connections had lower volumes in brain areas such as the hippocampus and amygdala, which play a role in memory and are affected by dementia.
Study authors also found that white matter lesion volume increased significantly with less frequent social contact — 0.30 percent in the lowest frequency group versus 0.26 percent in the highest frequency group.
Previous research has linked white matter lesions to a higher risk of cognitive impairment, dementia, depression, and stroke.
Depression May Contribute to a ‘Vicious Cycle’ of Isolation
The investigative team noted that symptoms of depression partly explained the relationship between social isolation and brain volumes. These depression symptoms, however, accounted for only 15 percent to 29 percent of the association.
“People who are socially isolated may become depressed, and the onset of Alzheimer's disease is associated with depression 30 to 40 percent of the time,” says Dr. Fillit, who was not involved in the study. “Cognitive decline then can lead to more isolation and depression. It’s a vicious cycle.”
How Loneliness May Cause Physical Damage
Isolation can cause health damage that goes beyond the brain. The National Council on Aging warns that loneliness may raise the risk of high blood pressure, heart disease, obesity, a weakened immune system, anxiety, and death.
Previous research indicates that loneliness may contribute to inflammation and oxidative stress, which in turn can affect blood vessels. Joel Salinas, MD, a clinical assistant professor of neurology at NYU Langone Health in New York City, points out that this effect on the blood vessels may be a reason behind brain shrinkage as well. Dr. Salinas, who was not involved in this study, also serves as the chief medical officer at Isaac Health, an in-home memory clinic for brain health and memory issues in New York City.
The authors emphasize that the study does not prove that social isolation causes brain shrinkage; it only shows an association. They also point out that the investigation was limited to only older Japanese people, so results may not be generalizable to people of other ethnicities or younger people.
“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,” said Ninomiya.
How Seniors Can Connect to Maintain the Brain
Older adults frequently deal with feelings of loneliness and social isolation, according to Mirnova E. Ceide, MD, an associate professor of geriatric psychiatry and geriatrics and associate director of psychiatry at the Montefiore Center for the Aging Brain in Yonkers, New York.
“We see up to 40 percent of older adults experiencing social isolation,” says Dr. Ceide, who did not contribute to the paper. “Essentially, when you're socially isolated, you’re not stimulating your brain, and as with any kind of organism, it needs stimulation. We see the brain acting differently when you’re not getting that stimulation that you normally would from interacting with people regularly. It’s a ‘use it or lose it’ situation.”
It can be harder to meet new people as we age, but Ceide urges older folks to be proactive about developing and keeping up relationships. She often advises her patients to reach out to their state department of aging, which typically has contact information for senior centers and other local organizations that work with older adults and put together group events, outings, and classes. The federally run Eldercare Locator offers a similar directory, connecting the public to services for older adults and their families.
The National Institute on Aging encourages older people to explore activities such as:
- Playing cards
- Group travel
- Video chats with friends and family
- Trying new restaurants
- Taking up a group hobby such as knitting, birdwatching, and painting
- Reconnecting with old friends through your high school or college alumni association
From his own research, Salinas has observed that simply having someone available most or all of the time whom you can count on to listen to you when you need to talk is associated with greater cognitive resilience.
It’s also good to consider your hobbies. “It's really great to find groups of people who have similar interests, because it helps to increase the likelihood that you'll make a connection with somebody that's reciprocal,” he says.