How loneliness damages the brain and the health of the elderly

Abandoning the elderly to the fate of their supervening loneliness is an unforgivable cruelty that no civilized society should allow. In Western countries, it is estimated that 20 to 40% of the elderly feel lonely. In Spain, a recent survey by the National Institute of Statistics (INE) found that of the almost 5 million people (4,981,696) who live alone in homes, more than 2.54 million are 60 or older and 1.71 million are 70 or older.

But loneliness is about more than lacking company. Even in the middle of a crowd, one can feel more alone than ever. The feeling of loneliness comes when a person’s need for human intimacy is not being met. In other words, loneliness can also consist of living in the company of someone who does not love you or does not care for you, which explains the feeling of many older people, who in some degree, have been abandoned to their fate. It is also true that not all older people who live alone feel lonely.

Loneliness can do a lot of damage, especially to older people. It has been found that the perception of loneliness is a better predictor of people’s physical and mental health than the size of their social network — the number of family members, friends or people they hang out with — or even their marital status. There are numerous health and social factors that contribute to the feeling of loneliness. Generally, it begins when the elderly start to lose emotionally close relationships, such as those they had with their deceased loved ones or friends. From then on, these people may tend to focus more on the emotional memory of the loss than on seeking new social relationships that could fill in the gap. Loneliness of the elderly is often related to poverty, and there are studies that indicate that it is not always related to age.

The subjective experience of loneliness is a source of stress that negatively affects people’s somatic and mental health. Neuroscience and psychobiology have linked it to an increased risk of cognitive impairment and dementia, as well as poor self-esteem, sleep disorders, memory loss and loss of emotional regulation, which is what allows people to mentally adjust to a particular situation and improve their well-being. These alterations could derive from changes in the brain, with new studies linking loneliness to a smaller volume of gray matter in some regions,

Using structural and functional neuroimaging, scientists from prestigious universities and research centers in Germany and the United Kingdom carefully investigated the brain correlates of loneliness in older adults. The idea behind the research was that different ways of feeling and perceiving loneliness could reflect anatomical differences in certain brain structures. To verify this, the researchers — using functional magnetic resonance techniques — explored the brain of 319 elderly people, aged between 61 and 82 years, with a nearly even gender split.

The results, published in the prestigious Scientific Reports of the Nature group, showed that individuals who scored higher on perceived loneliness according to the UCLA Loneliness Scale (a commonly-used measure developed by the University of California) tended to have lower volume of gray matter in the amygdala, hippocampus, and cerebellum, generally in the left hemisphere of the brain — regions that have been linked to emotional and social information processing. The volume of the amygdala, specifically, has also been related to the size of people’s real and online social network.

Although they are just correlations, these results could be interpreted as a reflection of a person’s social interaction throughout life. In other words, having more friends, being part of groups, going out more, etc., could cause the amygdala to grow. While loneliness, lack of social interaction, staying locked up at home and not going to activities with other people, could have the opposite effect: it could cause the amygdala to shrink. It may also be the case that individuals who have a larger amygdala — for genetic or other reasons — are more socially inclined. The researchers believe, however, that the stress of loneliness damages the hippocampus of the elderly and reduces its volume, increasing the level of the hormone cortisol and raising blood pressure. This in turn would affect memory and could be worsened by lack of social interaction.

This conclusion appears to be backed by research from Iranian universities and research centers, which argues that loneliness is an immunometabolic syndrome of multifaceted pathology, since it alters the cellular levels of inflammatory cellular substances, reduces the body’s response to antibodies that protect us from disease, reduces substances that promote cell growth, and alters cardiovascular and mental functions. That’s according to a review on the subject published in November 2021 in the International Journal of Environmental Research and Public Health.

However, another group of researchers, led by psychobiologist Alicia Salvador from the University of Valencia in Spain — who has also been carrying out important work on the consequences of loneliness for people’s health —, questions the relationship between cortisol and loneliness, linking it rather to physical and psychological health. This impact is especially seen among men, who are therefore considered more vulnerable to loneliness.

In short, whatever its causal mechanisms, the observations and experimental research are clear about the negative consequences of loneliness on the physical and mental health of the elderly. This should not only motivate families to spend more quality time with elderly relatives, but also encourage political administrations to establish programs and provide economic resources so that the elderly can enjoy an active social life and not fall victim to loneliness.

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