Elderly people who are socially isolated are at an increased risk of death regardless of whether they believe they are lonely or not.

“Social connections can provide emotional support and warmth which is important but they also provide things like advice, making sure people take their medication and provide support in helping them to do things. It would suggest that those practical aspects are quite important for older people's survival. There's been such an increase in people living alone. In the last 15 years, the number of 55 to 64-year-olds living alone has increased by 50%. And it might be that people in those circumstances aren't looking after themselves so well”, lead researcher Prof Andrew Steptoe said.
The study has been published in the Proceedings of the National Academy of Sciences.
Source-Medindia