When you’re five, your friends share their peanut butter and jelly sandwiches when you forget your lunch at home. In your 20s, they help you choose a fulfilling career. A decade later, they make you laugh when the stress of a family and a full-time job start to wear you down. In your 50s, your friends help you plan for your retirement. Once you retire, they invite you to join them for a weekly round of golf and encourage you to volunteer at the library.

True friendships enrich our lives in so many ways. But can they do more? Can they actually help us live longer?

Research over the past 25 years has shown that social relationships can have a positive effect on survival in older adults. But these studies have left many questions unanswered. For example, are all social relationships equally beneficial? Do relationships with our children and other relatives help us as much relationships with close friends and confidants?

In an article published in the July 2005 Journal of Epidemiology and Community Health , researchers report that older adults with a strong network of friends were significantly less likely to die over a 10-year period than older adults with a smaller network of friends. Strong social ties with children or other relatives, on the other hand, did not positively affect survival.

About the Study

The researchers drew on data from the Australian Longitudinal Study of Aging (ALSA). ALSA began in 1992 and was designed to assess the effects of social, biomedical, behavioral, economic, and environmental factors on the health and well-being of older adults.

The current study was based on 1,477 ALSA participants, aged 70 years and older. The researchers had extensive information about each participant, including age, gender, income, education, physical and mental health status, disabilities, cognitive function, smoking status and activity level.

The participants had also described their social networks, which the researchers broke down into four categories: children, relatives (excluding children and spouse), friends, and confidants (including spouse). Based on the level of personal and phone contact and the number of individuals in each network, the researchers ranked the strength of the participants’ networks into upper, middle, or lower thirds.

The researchers then noted how many study subjects in the upper, middle, and lower thirds of each social network category died over the next 10 years.

The Findings

The researchers found that participants with the strongest network of friends were significantly less likely to die over the 10-year period of the study than participants with the weakest network of friends. This was true even after adjusting for demographic, health, and lifestyle factors, such as age and smoking status, which are known to affect mortality.

Participants whose network of confidants ranked in the middle or upper third had a significantly higher chance of surviving over the decade compared to those in the lowest third. However, the protective effect of confidants was not as strong as that of the friends.

A strong social network of children and relatives did not have a significant effect on mortality.

This study had two important limitations. First, ALSA did not provide any data about the participants’ diet, which could have had a considerable impact on mortality. Second, ALSA was not originally designed to study the effects of social networks on mortality, a flaw that may lead to certain biases.

How Does This Affect You?

This study demonstrated that older adults with a strong network of friends and confidants lived longer than those with the fewest friends or confidants. Perhaps surprisingly, strong networks of children or other relatives did not affect longevity.

It is not yet known why friends have such a strong effect on mortality. Perhaps, as the researchers speculate, friends can positively affect health behaviors such as smoking, provide encouragement to seek medical help, or have a positive impact on mood, morale, and self esteem. It is this last potential explanation that may differentiate the beneficial influence of friends over relatives.

Few would argue that a collection of intimate, trustworthy friends can improve the quality of life immeasurably. Interestingly, it now appears that these same friends can measurably affect its duration. So, it may be well worth the extra effort it takes to stay in touch. The laughter, support, and companionship that you receive from—and give to—your friends may help keep you alive longer. As for your children…well, at least there’s no evidence they shorten your life.