Loneliness and social isolation are linked to specific proteins – new research

Understanding the impact of social isolation and loneliness on health through proteomics, emphasizing the importance of meaningful social connections.

Human beings are inherently social. We thrive on connection, communication and shared experiences, which help shape our identities and foster a sense of belonging. Yet, in an increasingly digital and fast-paced world, feelings of loneliness and social isolation have become alarmingly common.

The World Health Organization (WHO) has stated that these feelings are widespread. About 25% of older people experience social isolation and 5%-15% of adolescents feel lonely.

These figures are important since published studies have demonstrated that social isolation and loneliness are linked to increased risk of disease and death. Indeed, our own study, published in 2022, found that social isolation in older people carried a 26% increased risk of developing dementia. We also found that loneliness was associated with depression.

We wanted to follow up our previous study by understanding the underlying biological processes behind this link between social isolation and loneliness and health. Why is loneliness so bad for our bodies and minds?

We focused on proteomics, the study of proteins. This is because we know that proteins play a role in gene expression, the process by which the information encoded in a gene is turned into biological activity. Proteins are also a major source of drug targets for developing medications.

In this collaborative study between the University of Cambridge and Fudan University, published in Nature Human Behaviour, we used data from 42,062 participants from the UK Biobank and studied 2,920 plasma proteins.

We investigated the association between proteins and self-reported loneliness and social isolation. We discovered that the proteins found to be significantly associated with loneliness and social isolation are also known to be implicated in inflammation as well as antiviral and immune responses.