Researcher at Brigham Young University say strong social connections can extend a person's lifespan. (iStock)

New research from Brigham Young University suggests that social relationships can predict a person's odds of living or dying.

The researchers found that social connections can improve the odds of survival by 50 per cent.

According to the study, published in the peer-reviewed journal PloS Medicine, a lack of social contact is as damaging as smoking 15 cigarettes a day or being an alcoholic.

The researchers also suggest a lack of social interaction can be more harmful than not exercising and is twice as harmful as being obese.

'That sense of purpose and meaning translates to taking better care of themselves and taking fewer risks.'—Julianne Holt-Lunstad, BYU professor

They came to that conclusion after reviewing 148 previously published studies that measured the frequency of human interaction and tracked health outcomes for an average of 7½ years.

"When someone is connected to a group and feels responsibility for other people, that sense of purpose and meaning translates to taking better care of themselves and taking fewer risks," said BYU professor Julianne Holt-Lunstad, a co-author on the study.

The researchers say relationships provide a level of protection for people of all ages.

"We take relationships for granted as humans. We're like fish that don't notice the water," said Timothy Smith, the other author on the study.

"That constant interaction is not only beneficial psychologically but directly to our physical health," he said.