Older people who are very lonely are at an increased risk of dying prematurely, new research indicates.

US researchers looked at the differences in the rate of decline in both mental and physical health as people get older. This included examining the importance of relationships to older people.

The study found that extreme loneliness had major consequences when it came to health, including disrupted sleep, increased depression, higher blood pressure and even altered immune cells.

Overall, those who were extremely lonely had a 14% increased risk of dying prematurely. This was nearly as strong as the impact of coming from a disadvantaged background - this was found to increase the risk of early death by 19%.

According to lead researcher, Prof John Cacioppo, of the University of Chicago, older people should try to remain in touch with former work colleagues, as well as family and friends. This will provide them with an opportunity to connect with others who they care about and who care about them.

He said that retiring to the sun ‘isn't necessarily a good idea if it means you are disconnected from the people who mean the most to you'.

"We are experiencing a silver tsunami demographically. The baby boomers are reaching retirement age. People have to think about how to protect themselves from depression, low subjective wellbeing and early mortality," Prof Cacioppo warned.

He acknowledged that some people like to live alone, however he insisted that most people ‘thrive from social situations in which they provide mutual support and develop strong rapport'.

He also pointed out that it is not necessarily physical isolation or solitude that affects a person, but rather a subjective sense of isolation. In other words, a person may live alone, but not be lonely if they enjoy a good social life and the company of those around them.

Prof Cacioppo and his colleagues presented their findings at the American Association for the Advancement of Science Annual Meeting in Chicago.