London, Sep 14 (IANS) Your friends might help you live longer without your knowing it. A new study says that those surrounded by family and friends are 50 percent less likely to die early than those with no social life.

Socially-connected people live an average of 3.7 years longer. Researchers compared the impact of friends with the effects of quitting smoking, reports the Daily Mail.

Loners with little social support have a mortality as high as alcoholics and even higher than those affected by obesity or physical inactivity, the study found.

The researchers analysed data from 148 studies over three decades involving more than 300,000 people.

"Friends and supportive people can make life easier on a basic, everyday level," said Bert Uchino of Brigham Young University in the US, who led the study.

"They can lend you money, offer lifts or provide baby-sitting. They can also encourage you to have better health practices, see a doctor, exercise more. They may also help you indirectly by making you feel you have something to live for," Uchino said.

He said the emotional support people receive from friends and loved ones "can help you think about problems in ways that decrease their perceived severity or even make them non-problems."

"If patients do have good social relationships, they should maintain them. If they don't, they should try to foster them," he added.