Isolation from family members reduces brain volume in the elderly – 07/12/2023 – Health

Elderly people who live socially isolated, rarely meeting or interacting with friends and family, have greater loss of brain volume and symptoms of depression, a condition that, in the long term, increases the risk of neurodegenerative diseases, such as dementia.

A new study, conducted with 8,896 elderly people in Japan without a previous diagnosis of dementia, indicated that the loss of brain volume was greater in those who lived in isolation (67.8% against 67.3%), as well as the lesions were on average 0. 27% higher in this group.

Although these values ​​are small in difference (about 0.75% variance), they are statistically significant and demonstrate a clear association of loneliness with these negative effects on brain shrinkage, say the authors.

The research came out on Wednesday (12) in the specialized journal Neurology, published by the American Academy of Neurology, with support from the Japan Agency for Medical Research and Development. The study was coordinated by scientist Toshiharu Ninomiya, from the Department of Epidemiology and Public Health at the University of Kyushu (Japan).

Social interaction is important at all stages of life, but in older individuals it can be essential to maintain well-being and quality of life.

Although it is still difficult to associate isolation with brain atrophy, the feeling of loneliness can lead to harmful effects on the brain, such as the loss of important brain connections and the increase in microlesions in the brain white matter (composed of the long axes of neurons and responsible for the electrical connection between them).

To reach this conclusion, the scientists analyzed the neurological MRI scans of approximately 10,000 elderly people included in the JPSC-AD (Japanese Collaborations for Prospective Studies in Aging and Dementia) research, a national population study that seeks to assess risk factors for advanced neurodegenerative disease.

Afterwards, those without a previous diagnosis of dementia were selected and asked about the frequency of social interaction —How often do you have contact with friends and family who do not live in the same house as you (for example, face-to-face meeting or telephone)?—, with a multiple-choice answer option—every day, several times a week, several times a month, and rarely.

Approximately 6 out of 10 (57%) were women, and the median age was 73 years.

Crossing the patients’ responses with the imaging tests and adjusting for other variables, such as education, presence of comorbidities and others, they saw that the proportion between brain volume and intracranial box decreased the lower the frequency of social interaction. This means, in practice, that loss of brain mass (connections) occurs in people who face isolation more often than in those who interact more socially.

Furthermore, there was a positive association between the presence of brain white matter lesions and lower frequency of social interaction.

As depression symptoms can also affect the brain, the scientists also analyzed whether these were aggravated by the number of interactions and whether this also affected brain volume. In general, from 15% to 29% of the associations between smaller brain volume and isolation had depressive symptoms as the main cause.

The research was the first to use a large national database and point out an association between social isolation and loss of brain volume. According to the authors, there was also a reduction in some important brain areas linked to feelings, such as the amygdala (responsible for emotional responses related to social behavior in humans and other mammals) and the hippocampus (associated with emotions, motivation, hormonal activity, activity autonomic and memory formation).

The temporal lobe and hippocampus, according to studies, are some of the first areas affected in Alzheimer’s disease. Reduced connection and mass in these areas can thus lead to damage associated with cognitive loss and dementia progression.

The study has some limitations, such as the fact that individuals who reported the least social contact already had a higher incidence of comorbidities, such as diabetes, hypertension and unhealthy lifestyle habits, which are also risk factors for dementia.

It was therefore necessary to adjust these differences for comorbidities, isolating the verified effects of other factors on cognitive loss. The final analysis shows an association between loss of brain volume and low social frequency, also indicating that regaining contact with family members can reverse this effect and attenuate the associated depressive symptoms in the elderly.