Loneliness has long been associated with ill health, but researchers have made fresh insights into the link between the two. While poor health can result in people becoming isolated and lonely, studies have also suggested that loneliness itself can lead to poorer health.
Researchers at the University of Cambridge used data from over 42,000 participants in the UK Biobank project to explore whether social isolation and loneliness had different levels of proteins in their blood compared to those who were not socially isolated or lonely. They found that people who reported social isolation had higher levels of 175 proteins, many of which are involved in inflammation, antiviral responses, and the immune system.
The researchers also studied data that tracked the health of participants over a 14-year period and found that around 90% of these proteins were linked to the risk of mortality. Additionally, about 50% of the proteins were linked to cardiovascular disease, type 2 diabetes, and stroke.
While the study did not find any protein that caused social isolation or loneliness, it did find that five specific proteins influenced levels of inflammation and metabolic markers in people who experienced loneliness. These findings partly explained the association between loneliness and cardiovascular disease, stroke, and mortality.
The researchers suggest that while the effects may be small, they are significant, as levels of one protein, known as ADM, could explain around 7.5% of the association between loneliness and the risk of four diseases and mortality.
Experts agree that the study supports previous research indicating a link between loneliness and physical health problems, possibly due to systemic inflammatory processes induced by stress. However, some researchers suggest that stress-related health behaviors, such as heavy alcohol consumption and low physical activity, may be even more significant factors contributing to the health impacts of loneliness.
Source: https://www.theguardian.com/society/2025/jan/03/loneliness-ill-health-protein-levels-research