Social isolation raises risk of heart disease, Cambridge research reveals

Cambridge research has found that loneliness can increase proteins which fur up the arteries and may trigger early death.

Loneliness is lethal because it increases proteins which fur up the arteries and may trigger early death, a study suggests.

Interactions with friends and family may keep us healthy because they boost our immune system, reduce our risk of conditions such as heart disease, stroke, and type two diabetes, the University of Cambridge found.

Scientists studied the blood of more than 42,000 people enrolled in the United Kingdom’s Biobank, a long-term health-monitoring project, looking for internal differences in people who were socially isolated.

The team calculated social isolation and loneliness scores for individuals based on whether they lived alone, how frequently they have contact with others socially, and whether they take part in social activities. They also measured whether they “felt” lonely.

There were five proteins in the study whose abundance was caused by loneliness. Photo / 123rf

The team found five proteins whose abundance was caused by loneliness.

One of the proteins, ASGR1, is associated with higher cholesterol and an increased risk of cardiovascular disease, while other identified proteins play roles in the development of insulin resistance, atherosclerosis (“furring” of the arteries) and cancer progression.

Dr Chun Shen from the Department of Clinical Neurosciences at the University of Cambridge and the Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University in China, 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.”

Previous studies have found that social isolation is a major health problem that can increase the risk of premature death by 14%, while loneliness raises the risk of stroke and heart disease by 30%.

However, until now, scientists have been unsure what is driving the phenomenon.

One of the proteins produced in higher levels as a result of loneliness was ADM. High ADM levels were found to be linked to smaller brain volume in some regions, and an increased risk of early death.

The team also found 175 proteins that were associated with social isolation, many of which are produced in response to inflammation, viral infection, and as part of our immune responses, as well as having been linked to cardiovascular disease, type two diabetes, stroke, and early death.

‘Social contact keeps us well’

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 World Health Organisation 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.”

The study, which was carried out alongside the University of Warwick and Fudan University in China, was published in the journal Nature Human Behaviour.

Professor Jianfeng Feng, from the University of Warwick, added: “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.”