Loneliness linked to heart disease, strokes and infections

Those looking to boost their health might want to check their social calendar – as researchers have found that loneliness is linked to a higher risk of heart disease, stroke and infections.

‘We need to find ways to tackle this growing problem [loneliness] and keep people connected to help them stay healthy.’ Picture: iStock

Those looking for an easy way to boost their health this year might want to check their social calendar, as well as heading to the gym – as researchers have found that loneliness is linked to a higher risk of heart disease, stroke and infections.

Researchers from the UK and China have found that some blood proteins might increase as social isolation gets more pronounced, increasing the risk of developing several conditions and diseases.

The World Health Organisation (WHO) has said that loneliness is among the most significant global health concerns, affecting every facet of health, wellbeing and development. It has long been understood that loneliness affects health but scientists now think that the mechanism behind this link could be in the blood.

The team, from the University of Cambridge and Fudan University, in China, studied blood proteins from more than 42,000 adults from the UK Biobank, taking scores for loneliness and social isolation from each participant.

They found five proteins with a causal link to loneliness – including some with crucial associations to cholesterol levels and insulin resistance.

The authors of the research said that some blood proteins play a “key role” in the relationship between social connection and health, with some even increasing “as a direct consequence” of a lonelier life.

Professor Barbara Sahakian from the department of psychiatry at the University of Cambridge said: “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 WHO 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.”

One of the proteins linked to loneliness – called adrenomedullin (ADM) – plays a crucial role in responses to stress.

The study, published in Nature Human Behaviour, found another protein, ASGR1, was associated with loneliness, higher cholesterol and increased risk of heart disease. Another was associated with insulin resistance, which is a precursor to type 2 diabetes.

Social isolation is a multi-generational issue. Picture: iStock

Dr Chun Shen, from the University of Cambridge and the Institute of Science and Technology for Brain Inspired Intelligence at Fudan University, said: “We know that social isolation and loneliness are linked to poorer health, but we’ve never understood why. 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.”

Professor Jianfeng Feng from the University of Warwick said: “The proteins we’ve 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.”

Previous research has found that loneliness could have a similar impact on health as smoking 15 cigarettes a day.

Another study, published in 2023, found that pensioners in China who reported socialising daily, weekly or monthly lived longer than those who did so only occasionally or not at all.

The paper, published in the Journal of Epidemiology and Community Health, reported a death rate of 18.4 per 100 people each year among those who never socialised. The rate fell rapidly as socialisation increased to 7.3 among those who interacted with others nearly every day.

The Times