Research suggests social connection helps prevent heart disease, stroke and type 2 diabetes
Researchers from the United Kingdom and China have revealed biological evidence that social relationships impact our health.
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Having social time with friends and family helps us unwind, laugh and share experiences. It makes us feel good because we’re a part of something meaningful, whether it’s a 10-minute check-in by phone with our parents or an evening out with an old friend.
Those feel-good vibes are important for mental and physical health, boosting immunity and combatting loneliness that can creep up if life gets too busy and overwhelming (and we don’t make time for social connections). Or if we start to disengage from things we enjoy, which can happen to anyone, but often hits seniors living alone who aren’t involved in social activities. Almost one in five Canadians seniors 65 and older reported experiencing loneliness, according to Statistics Canada.
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The benefits of social time are tangible. Researchers from the United Kingdom and China have revealed biological evidence that social relationships impact our health. They studied proteins from the blood samples in the UK Biobank that identify the underlying mechanisms at work that support health. Findings were reported recently in the journal Nature Human Behaviour.
Blood proteins affected by social connections
Proteins circulating in the blood are essential to human health. The proteins are molecules produced by our genes to help the body make hormones, enzymes and antibodies that have a role in functions like growth, metabolism, mood and immunity. Scientists use these blood proteins as drug targets to develop therapies for diseases.
The research team of scientists at the University of Cambridge, U.K., and Fudan University, China, looked at the suite of proteins called proteomes in blood samples donated by more than 42,000 adults aged 40 to 69 years. From the samples, they determined which proteins were in higher levels for people who were lonely or socially isolated. They could also investigate how these specific proteins were connected to poorer health.
There’s mounting evidence that both social isolation and loneliness are linked to poorer health and an early death. A 2022 meta-analysis of 90 studies that had examined the links between loneliness, social isolation and early death among more than two million adults concluded that people who experienced social isolation had a 32 per cent higher risk of dying early from any cause compared with those who weren’t socially isolated. Participants who reported feeling lonely were 14 per cent more likely to die earlier than those who did not.
Loneliness is a subjective feeling that undermines health
For the U.K. China project, researchers determined social isolation and loneliness scores for the individuals, noting the difference between the two: social isolation is an objective measure which factors in whether a person lives alone, if they participate in social activities and how often they interact with people socially. Loneliness, by comparison, is a subjective measure based on whether a person feels lonely.
The analysis of the proteomes, after adjusting for age, sex and socioeconomic background, showed 175 proteins associated with social isolation and 26 proteins associated with loneliness, with overlap of about 85 per cent of the proteins linked with loneliness shared with social isolation.
Proteins linked to these parameters were involved in inflammation and antiviral responses as part of immune system responses. More than half of these proteins were linked to cardiovascular disease, stroke, type 2 diabetes and mortality during a 14-year follow-up.
“We know that social isolation and loneliness are linked to poorer health, but we’ve never understood why,” Dr. Chun Shen from clinical neuroscience studies at the University of Cambridge and the Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University said in a university report on the study. “Our work has highlighted a number of proteins that appear to play a key role in this relationship, with levels of some proteins in particular increasing as a direct consequence of loneliness.”
The authors note that there are more than 100,000 proteins and many of their variants in the human body. AI and high throughput proteomics can help researchers pinpoint key proteins in prevention, diagnosis, treatment and prognosis in many human diseases. For this study, the proteins that were identified help provide targets for the biology behind poor health for people who are socially isolated or lonely. The evidence builds on the case for promoting social relationships for health and well-being.
People need love hormones to boost immunity
Interesting to note as well, one of the proteins produced in higher levels as a result of loneliness was ADM. This protein helps people respond to stress, regulating stress hormones and social hormones such as oxytocin, the so-called “love hormone,” that can reduce stress and boost mood.
Higher ADM levels were linked to lower volume of the left caudate, a brain region that’s involved in emotional, reward and social processes. Also, higher levels of ADM were linked to increased risk of early death. We need those feelings of love and connectedness to live long, full lives.
ASGRI, another of the proteins identified is linked to higher cholesterol and higher risk of cardiovascular disease. Other proteins contribute to the development of insulin resistance, cancer and atherosclerosis, the buildup of plaque on arteries that leads to blocked blood flow.
As psychiatry professor Barbara Sahakian at the University of Cambridge said in the university report, “These findings drive home the importance of social contact in keeping us well. More and more people of all ages are reporting feeling lonely. That’s why the World Health Organization has described social isolation and loneliness as a global public health concern. We need to find ways to tackle this growing problem and keep people connected to help them stay healthy.”
