"Social isolation is associated with a higher risk of death in older people regardless of whether they consider themselves lonely," BBC News has reported.

Previous research has suggested that people who have limited social contact are at increased risk of death. Many researchers have suggested that this is possibly due to the emotional effects of isolation – that feeling lonely is bad for health.

But this new, large UK study implies that the relationship between social isolation, feeling lonely and risk of death is more complex. The researchers looked at whether these factors were linked in a large group of UK adults aged 52 or above.

The study found that both social isolation and loneliness were associated with increased risk of death. However, if demographic factors and initial health were taken into account, loneliness was no longer significantly associated with risk of death. There was still a significant link between social isolation and risk of death, however, after these other factors and even loneliness had been taken into account.

This suggests that factors other than loneliness – such as having no-one to check on a person’s health – may contribute to increased risk of death.

Efforts to reduce social isolation are likely to have positive outcomes for wellbeing and mortality rates.

The study was led by epidemiologist Andrew Steptoe of University College London and colleagues that was published in the Proceedings of the National Academy of Sciences this week.