"We used baseline data on loneliness in 2009 as a predictor of mortality in 2011. We found that people who perceive themselves as lonely were 10 per cent more likely to die," says Chan.

Chan's analyses include three aspects of loneliness: physical (who you live with), social (neighbours and friends you engage with), and perception of loneliness (based on the UCLA Loneliness Scale, a commonly used measure of loneliness).

After controlling for variables, the only factor that remained significant in determining likelihood of death was a person's perception of their loneliness.

This finding has an impact on the Singapore government's efforts to promote multigenerational living arrangements, Chan says. "We found that who you live with doesn't matter. Whether you live alone, with a spouse or with children, living arrangements do not have an impact on mortality," she says.

Chan's team is revisiting the group of elderly again this year to collect more data points to bolster their analyses.

Having collected blood samples in the past, her team will be analysing markers of inflammation and levels of stress hormones such as cortisol to quantify the correlation between loneliness and health. This year, they will also take cheek swabs to analyse cortisol levels in saliva.

Chan's findings agree with studies in the US conducted by John Cacioppo, a professor of psychology at the University of Chicago. He found that extreme loneliness can increase an older person's chances of premature death by 14 per cent.

Cacioppo's team has done many studies into the health risks associated with loneliness in the elderly. They have found dramatic consequences to health such as sleep disruption, elevated blood pressure, rises in cortisol, altered gene expression in immune cells, increased depression and lower overall feelings of well-being.

"We are experiencing a silver tsunami, demographically. The baby boomers are reaching retirement age. Each day between 2011 and 2030, an average of 10,000 people will turn 65," he says. "People have to think about how to protect themselves from depression, low subjective well-being and early mortality."

Cacioppo's team wanted to find out how loneliness affects our physical bodies. Looking at the brain, they used functional MRI scans to study people who identified themselves as lonely and compared them with those from people who were not lonely. They found differences in activity in two brain regions: the ventral striatum and the temporoparietal junction.

The ventral striatum is the region of the brain associated with rewards such as food, money and possibly social rewards and feelings of love. The temporoparietal junction is the region associated with taking the perspective of another person.

The scientists found that both the ventral striatum and the temporoparietal junction were much more activated in non-lonely people than in lonely.

"Given their feelings of social isolation, lonely people may be left to find relative comfort in non-social rewards," Cacioppo says.

Loneliness can also raise blood pressure, increasing the risk of stroke and heart disease. Cacioppo's team found lonely people have blood pressure readings that are up to 30 points higher than those of non-lonely people.

Interestingly Cacioppo, together with scientists at Harvard University and the University of California San Diego, found that loneliness is contagious. Like a bad cold, loneliness can apparently spread among groups of people.

The researchers conducted a large-scale study that followed health conditions in people for more than 60 years. They found that lonely people tend to share their loneliness with others.

Gradually, a group of lonely people moved to the fringes of social networks.

"We detected an extraordinary pattern of contagion that leads people to be moved to the edge of the social network when they become lonely," Cacioppo says. "On the periphery, people have fewer friends, yet their loneliness leads them to losing the few ties they have left."

Before relationships are severed, people on the periphery transmit feelings of loneliness to their remaining friends, who also become lonely. This means that it is important for people to recognise loneliness and help those people connect with their social group before the lonely individuals move to the edges.

On the bright side, a positive outlook can reverse the negative health issues associated with a lonely life. Scientists at Concordia University in Montreal, Canada, followed 122 elderly people over six years. Using a questionnaire, they measured loneliness and strategies for positive thinking.

They also took saliva and blood samples from the participants to measure levels of cortisol and the inflammatory marker C-reactive protein.

While inflammation is a natural component of the immune system, chronic inflammation can cause many diseases and psychological disorders.

The researchers found that among lonely elderly, positive thinking was associated with lower levels of the protein.

Professor Carsten Wrosch, who led the study, says: "Older adults can be taught through counselling or therapy to engage in self-protective thoughts like staying positive when it comes to their own health."

Meditation can also help combat loneliness and the threats associated with stress and inflammation. Researchers at the University of California, Los Angeles found a simple meditation programme lasting just eight weeks could reduce loneliness in the elderly and also significantly reduce expression of inflammatory genes including C-reactive protein.

For those who need help dealing with loneliness, the most effective strategy found by scientists is to target social cognition, which refers to a person's thoughts about themselves and others.

The most useful interventions were those that helped people break out of the cycle of negative thoughts about self-worth and how people perceive them.

Cognitive behavioural therapy, a technique used for treating depression and eating disorders, was found to be particularly effective.

Project targets a wider circle of friends

A Singapore initiative has tried to foster new friendships for senior citizens and encourage activities together.

Project Engage was led by students from Nanyang Technological University’s Wee Kim Wee School of Communication and Information in a 10-week collaboration with the Southwest Community Development Council.

“We came up with five types of elderly: the learner, volunteer, nature lover, sporty and tech-savvy. Once we know what type the elderly person is, we can make recommendations based on their interests,” says Chandel Lim, 22, a member of the project team.

The first activity was held in January in tandem with Eco Day Out, an event to promote “green” living. The project team set up a booth to interact with senior citizens and distribute contact details of organisations that can provide social interaction. Door-to-door household visits by students was one strategy to raise awareness of their project, which wound up last month.

Abigail Chew, 61, a housewife for most of her life, lives with her husband and spends many happy hours with her children and grandchildren. She is not lonely, but believes it is very important to help others cope with loneliness. She volunteers four hours a week with the Sage Counselling Centre to man their helpline.

“The people who call the helpline are often lonely and depressed. We try to help them with basic problems and refer them to our counsellors if necessary,” says Chew.

She enjoys talking, and likes to connect with callers and find common topics of conversation. She heard about Project Engage through a church friend, and thinks it’s a great initiative.

“We can feel how these chats give [these people] moments of happiness,” Chew says.