A wideranging new study found that being lonely lowers our immune systems, increasing our chances of dying early. As a result, lonely people are 14 per cent more likely to die prematurely due to lower levels of virus-protecting white blood cells. The study concluded: "For older adults, perceived social isolation is a major health risk that can increase the risk of premature death by 14 percent."
Adding to the problem, the UK now has an ageing population, with older people more likely to live alone. Therefore more and more people are becoming socially isolated - with many dying before their time as a result.
Older people are more at risk
The 'danger signals' activated in the brain by loneliness ultimately affect the production of white blood cells
Professor John Cacioppo
Last night, charities warned that the general public now had a big role to play in combating the UK's loneliness epidemic - especially among the elderly.
Caroline Abrahams, Charity Director at Age UK said: "Contrary to what many people think, loneliness is not a normal part of ageing, and it not only makes life miserable, it can have a serious impact on your physical and mental health too.
"Research shows that more than a million older people say they haven't spoken to a friend, neighbour or family member for over a month and unless we act, our rapidly ageing population means we'll see ever greater numbers of lonely older people."
Latest figures from the Office of National Statistics show some 13 per cent of the population in England and Wales now live alone - amounting to 7.1 million people, an increase of 600,000 in the last decade.
The majority of these are living in homes with more than one bedroom, with older people most likely to be alone. But the new research suggests these people are more likely to die earlier than is necessary. Researchers stressed that their findings were independent of other factors such as depression, stress and social support.
The study tallied with earlier findings that loneliness leads to fight-or-flight signalling occurring in the body, which subsequently leads to a drop in white blood cells, weakening the immune system. Professor John Cacioppo, lead author of the study, explained: "Taken together, these findings support a mechanistic model in which loneliness results in fight-or-flight stress signalling, which increases the production of immature monocytes, leading to up-regulation of inflammatory genes and impaired anti-viral responses." He added: "The 'danger signals' activated in the brain by loneliness ultimately affect the production of white blood cells.
"The resulting shift in monocyte output may both propagate loneliness and contribute to its associated health risks." The University of Chicago scientists examined gene expression in 'leukocytes', cells responsible for protecting us against bacteria and viruses. They established a link between loneliness and a phenomenon called 'conserved transcriptional response to adversity' (CTRA).
CTRA describes the effect of lonely people tending to have a weaker immune system response than those with a healthy social life. It occurs when the number of genes involved in inflammation increases, while the number of genes involved in antiviral responses falls.
While confirming the findings of earlier studies, the new research also revealed that loneliness could predict future CTRA gene behaviour over a year later. The researchers found that loneliness and leukocyte gene expression appeared to provoke each other over time.
Additional research on monkeys found that the lonely primates also showed higher CTRA activity. Further tests found both lonely human beings and solitary monkeys had high levels of inflammatory damaging genes in their blood samples. The researchers also tracked HIV version of monkeys (simian immunodeficiency virus) in isolated primates. They found the altered antiviral gene expression in "lonely" monkeys allowed the condition to grow faster in both blood and brain. The ONS figures showed the proportion of people living alone in the UK increases gradually with age.
Currently, less than four per cent of those aged 16 to 24 live alone, while some 59 percent of those aged 85 and over live on their own.
With the population in the UK undoubtedly ageing, Mrs Abrahams hoped the new research would act as a wake-up call and she called on the public to help address the loneliness epidemic.
Loneliness lowers our immune systems, increasing our chances of dying early
She said: "We all have a role to play as individuals, families and communities in ensuring older people feel valued and included and that's why we're running our No one should have no one at Christmas campaign. "We are asking everyone to support lonely older people by donating and signing our petition calling on Government to recognise loneliness as a serious health problem and commit to action to help tackle it.
"There is something that everyone can do to help even if it's checking in on older neighbours, relatives and friends over the festive season and year round."