A recent study published in the journal Nature Human Behaviour unveils a direct link between loneliness, social isolation, and altered levels of proteins in the blood, offering new insights into how social factors can impact physical health. Researchers from the University of Cambridge and Fudan University in China analyzed blood samples from over 42,000 adults in the UK Biobank and discovered that individuals experiencing loneliness or social isolation had different levels of certain proteins associated with diseases and the risk of premature death.
The study found that people who feel lonely or socially isolated have altered levels of specific proteins in their blood compared to those who do not. "We know that social isolation and loneliness are linked to poorer health, but we've never understood why," said Dr. Chun Shen, the lead author of the study from Fudan University in China. "Our work has highlighted a number of proteins that play a key role in this relationship," Shen added, according to Earth.com.
The research team identified 175 proteins associated with social isolation and 26 proteins related to the feeling of loneliness. Notably, approximately 85% of the proteins associated with loneliness were shared with those related to social isolation, as reported by The Indian Express. Many of these proteins are involved in inflammation, antiviral responses, and the immune system, and were linked to serious conditions such as cardiovascular diseases, type 2 diabetes, strokes, and early death.
Among the proteins identified was adrenomedullin (ADM), which plays a role in responding to stress and regulating hormones like oxytocin, the "love hormone" that can reduce stress and improve mood. High levels of ADM were linked to structural changes in the brain's insula and caudate regions, which are essential for emotional and social processing, according to Earth.com. "Levels of some proteins, including ADM, increase as a direct consequence of loneliness," said Shen.
The study utilized a statistical method known as Mendelian randomization to confirm causal links between loneliness and specific proteins. The researchers found that loneliness directly influences the levels of five specific proteins. Four of these proteins are associated with brain regions that perform emotional and social tasks, while the fifth is linked to inflammation and metabolism.
Professor Jianfeng Feng from Fudan University noted the significance of these findings. "The proteins we have identified give us clues to the biology underpinning poor health among people who are socially isolated or lonely, highlighting why social relationships play such an important part in keeping us healthy," he said, according to Earth.com. The study sheds light on the biological pathways that connect social experiences with physical health outcomes.
The World Health Organization has defined social isolation and loneliness as a "global public health issue," emphasizing its impact on both older and younger populations, as reported by Mediafax. Reports indicate that people of all ages feel loneliness, and the urgency to address this threat to health is clear.
Professor Marko Elovainio from the University of Helsinki, who was not involved in the research, provided context on the study's importance. "This study strongly supports previous research findings that loneliness and social isolation are associated with numerous physical health problems," he said.
The article was written with the assistance of a news analysis system.