Loneliness may not speed up memory loss after all, study finds

Loneliness remains a public health concern. But while loneliness could “quietly affect how well older adults remember things,” a new study finds it might not be speeding up mental decline, as has long been suspected.

A European study that has tracked more than 10,000 people for seven years found that baseline memory was weaker in those who are lonely. But their memory didn’t deteriorate any faster than those who are not lonely. Rather than directly speeding up cognitive decline or dementia, loneliness appears to impact baseline brain performance, according to a release published in Science Daily.

At the beginning of the study, folks who said they were lonely didn’t score as well on memory tests as those who were not. But over time, the decline was no faster in one group than the other.

The findings were published in the journal Aging & Mental Health and used data from the “Survey of Health, Ageing and Retirement in Europe”, which is a long-term study of 10,217 adults ages 65 to 94 in 12 European countries.

Per the study, “These results add to evidence connecting loneliness with brain function in older adults, while also suggesting that isolation may not directly increase the risk of dementia.”

Screening for loneliness matters

Cognitive health assessments should include screening for loneliness as a matter of routine, according to the study team, which includes researchers from Universidad del Rosario in Colombia, the Clínica Universidad de Navarra and Universitat de Valencia in Spain, and the Karolinska Institute in Sweden.

They said in the release that tackling loneliness is an important way to support healthier aging.

“The finding that loneliness significantly impacted memory, but not the speed of decline in memory over time was a surprising outcome,” says lead author Dr. Luis Carlos Venegas-Sanabria, from the School of Medicine and Health Sciences at the Universidad del Rosario.

“It suggests that loneliness may play a more prominent role in the initial state of memory than in its progressive decline.” He added that the research “underscores the importance of addressing loneliness as a significant factor in the context of cognitive performance in older adults.”

Does loneliness impact dementia?

Loneliness and social isolation are not the same thing, though they can go hand in hand. In the study, loneliness was defined as “feeling alone.” A three-question survey allowed the researchers to classify the degree of loneliness as low, average or high. Those in the study were asked: “How much of the time do you feel that you lack companionship?” “How much of the time do you feel left out?” And also, “How much of the time do you feel isolated from others?”

They tested memory a few ways, including reading a list of 10 words aloud, then seeing how many a participant could recall in one minute. Memory was tested both immediately and after a delay.

They also controlled for factors that could influence memory, including physical activity, social engagement, depression scores, diabetes and other health conditions. People already diagnosed with a form of dementia were excluded as were those who could not perform certain activities of daily living because of physical limitations.

Loneliness and isolation both are often considered risk factors for dementia, but these researchers note that the different studies have not all agreed. Some say loneliness speeds up cognitive decline, while others have not found that connection.

This study looked at immediate and delayed recall over the seven years in the participants, who came from Germany, Spain, Sweden, and Slovenia, among other countries in central, south, north and eastern Europe.

No one disputes repeated studies showing health impacts of loneliness, including lifespan, mental health, anxiety, physical health and overall well-being. This study said they bolster evidence that shows loneliness and brain function in older adults are tied together, but they suggest isolation “may not directly increase the risk of dementia.”

Findings on memory and loneliness

According to the news release, more loneliness was reported in southern European countries, then eastern, northern and central Europe. The rates of loneliness ranged from 6% to 12%.

“Most participants (92%) reported low or average loneliness at the beginning of the study. Those in the high loneliness group (8%) tended to be older, more often female and reported poorer overall health. They also had higher rates of depression, high blood pressure, and diabetes,” per the research.

Those with high loneliness scored more poorly on delayed and immediate memory tests at the beginning of the study, compared to those who felt less lonely. But over the course of the study, they did not have faster memory decline. They were all comparable — including a “sharper drop in memory performance” across all three groups between year three and year seven.

There were limitations, including the fact that loneliness was treated as a fixed trait, rather than something that can ebb and flow and even disappear.