SYDNEY: Having social connections can improve our odds of survival by 50%, deeming a solitary lifestyle just as damaging as obesity, alcoholism and heavy smoking, scientists said.
Based on a review of 148 independent studies, lead researchers Julianne Holt-Lunstad and Timothy Smith from Brigham Young University, Utah, used data collected from 308,849 individuals over more than seven years, to determine how social relationships affected mortality.
“It is remarkable that a few questions about social relationships can predict whether people are alive or dead on average 7.5 years later,” Holt-Lunstad and Smith said.
A solitary lifestyle leads to shorter life
In assessing the level of each individual’s social relationships, the researchers measured them according to their ‘functional’ value – how the supported or lonely the individual felt – and their ‘structural’ value – the individual’s marital status, living situation and the size of their social networks.
They then compared these to the lifespans of the individuals, finding that those with strong social relationships are likely to remain alive longer than similar individuals with poor social relations.
The review, published in PLoS Medicine, legitimises the notion that a lack of social relationships is a risk factor for death, a connection which health organisations have been slow to recognise formally.
Risk not restricted to the elderly or mentally ill
The effect of human interaction on health remained the same, even when the researchers took into account various factors, including age, sex, initial health status and cause of death.
“The association between strength of social relationships did not vary over the lifespan: the effects are consistent regardless of the age of people investigated,” Holt-Lunstad and Smith said.
This means attention to a person’s social situation by health professionals should not be restricted to specific groups such as the elderly or mentally ill, according to the researchers. Treatments for the lonely may include an increased involvement in their community through social groups.
“In the past the focus has been on patients who have significant mental health concerns, so we know it’s very important to include this in their treatment, but in terms of general health and chronic health areas, the value of relationships is not such a standard question,” Frances Quirk from James Cook University said.
As harmful as 15 cigarettes a day
After quantifying the risk of death due to low social interaction, the researchers compared their results to well-known risk factors such as smoking and obesity.
Living a solitary life put subjects into a higher level of risk, equal to those who smoke 15 cigarettes a day, or those who are alcoholic, the researchers reported. It is also twice as harmful to a person’s health as obesity, and more damaging than a complete lack of exercise.
“We take relationships for granted as humans,” Smith said, noting modern conveniences and technology can lead us to neglect our social networks. “We’re like fish that don’t notice the water. That constant interaction is not only beneficial psychologically but directly to our physical health.”
Determining quality versus quantity
Because information on the nature of the relationships was not available – the data simply indicating whether or not an individual is integrated in a social network – the negative relationships, as well as the positive, were taken into account.
This means the researchers were unable to determine the different effects of a happy versus unhappy marriage on the survival of a person, and if mere acquaintances are enough to ward off premature death.
“There is now a need for more detailed research into what types of relationships are most important,”said Jocalyn Clark, the senior editor of PLoS Medicine. “Is it the quantity of relationships that make the most difference, or would benefits be felt from a small number of high quality relationships?”
The effect of marital status on mortality will be analysed in further studies by Holt-Lunstad and Smith. “Physicians, health professionals, educators and the public media take risk factors such as smoking, diet and exercise seriously,” they said. “The data presented here make a compelling case for social relationship factors to be added to that list.”
Original paper freely available from PLoS Medicine