In a 10-year study of nearly 1,500 people over 70 years of age, researchers at Flinders University found those with the most friends tended to live longer.

“Survival time may be enhanced by strong social networks,” said Lynne Giles, of the university’s department of rehabilitation and aged care.

“Among older Australians, these may be important in lengthening survival.”

Contact with children and other family members had little impact on the 10-year survival, the report found.

A network of good friends was, in statistical terms, equivalent to a 22 per cent reduction in the risk of dying during this period when compared to those who had close ties with their children or relatives.

The positive effect of having the support of friends was evident even if the person had been through major changes such as the death of a spouse or close family members, and the relocation of friends to other parts of the country.

Ms Giles and her colleagues assessed how economic, social, behavioural and environmental factors affected the health of elderly people.

The researchers monitored the participants annually for the first four years of the study and then at three-year intervals.

They also considered the impact of other factors such as health, lifestyle and socioeconomic status.

“We have shown that greater social networks with friends and confidants had significant protective effects against mortality over a 10-year follow-up period,” said Ms Giles.

The scientists suspect friends help to increase longevity by influencing behaviour such as smoking and drinking and helping people cope during difficult times.

In a commentary, Professor Anthony Jorm of the Australian National University in Canberra said the study supports the need for a clinical trail to see whether social networks have a health benefit for the elderly.

“These findings suggest what sort of interventions might be useful in improving the health of older people,” he added.