Social Connections Boost Health, Combat Disease Risks, Research Finds

Recent research highlights the significant impact of social interactions with friends and family on health, particularly in enhancing the immune system and reducing risks associated with diseases such as heart disease, stroke, and type 2 diabetes.

Conducted by researchers from the UK and China, the study analyzed blood samples from over 42,000 participants in the UK Biobank, with results published in the journal Nature Human Behaviour.

Importance of Social Connections

Social connections are increasingly acknowledged as essential for overall well-being, with studies linking social isolation and loneliness to health decline and higher mortality rates.

Despite this recognition, the biological mechanisms linking social interactions to health outcomes have remained unclear.

Research Findings and Methodology

The research team examined proteins in blood samples, which are essential for various bodily functions and important targets for therapeutic development.

This analysis aimed to uncover how social relationships influence health.

A collaborative effort between the University of Cambridge and Fudan University focused on studying blood samples from adults aged 40 to 69.

The research sought to determine which proteins were more prevalent in people experiencing social isolation and loneliness, as well as to explore the relationship between these proteins and health-related issues.

To measure social isolation, criteria included living alone and social engagement frequency, while loneliness was assessed through self-reported feelings.

After accounting for factors such as age and socioeconomic status, the researchers identified 175 proteins associated with social isolation and 26 linked to loneliness.

Notably, there was significant overlap, with approximately 85% of the proteins connected to loneliness also associated with social isolation.

Many of these proteins relate to inflammatory responses, viral infections, and immune system functions, while being associated with serious health problems like cardiovascular disease, type 2 diabetes, and premature death.

To gain insights into the causal relationships between loneliness, social isolation, and protein levels, the researchers utilized a statistical method known as Mendelian randomization, which underscored five specific proteins that increased in abundance due to feelings of loneliness.

Implications for Health and Society

This research elucidates the connection between loneliness and health, revealing several proteins that appear pivotal in this relationship, according to Dr. Chun Shen from the University of Cambridge.

The study points to the vast array of proteins in the human body and hints at the potential for artificial intelligence and advanced proteomic technologies to identify key proteins for preventive and therapeutic purposes, transforming the understanding of human health, as noted by Professor Jianfeng Feng from the University of Warwick.

Among the identified proteins was ADM, recognized for its role in stress responses and regulation of hormones affecting social behavior, such as oxytocin.

Increased levels of ADM correlated with a reduced volume of the insula (the brain region linked to bodily awareness) and the left caudate (associated with emotional and social processing), as well as an elevated risk of early mortality.

Another protein, ASGR1, was associated with higher cholesterol and increased cardiovascular risk, while others were linked to conditions like insulin resistance and cancer progression.

Professor Barbara Sahakian from the University of Cambridge highlighted the urgent need for maintaining social connections to promote health.

She pointed out the increasing feelings of loneliness reported across all age groups, indicating a public health crisis recognized by the World Health Organization.

It is critical to develop strategies that enhance social connectivity to improve health outcomes for people facing isolation.

Study Details:

• Title: Plasma proteomic signatures of social isolation and loneliness associated with morbidity and mortality.
• Authors: Chun Shen, Ruohan Zhang, Jintai Yu, Barbara J. Sahakian, Wei Cheng, Jianfeng Feng.
• Journal: Nature Human Behaviour
• Publication Date: 2025
• DOI: 10.1038/s41562-024-02078-1