It may be a relief to know that one of the best things you can do for your health does not involve diet or exercise. That is not to say these are unimportant, but our social relationships also play a big role in our physical health. Having closer social ties is one of the key predictors of longevity.

Exactly how relationships lead to better health, and what people and policy makers can do to help spread awareness of the connection, is the subject of a special edition of the American Psychological Association’s journal, American Psychologist.

Having others to talk with and rely on during tough times can ease the wear and tear of the stress response.

The range of social relationships affecting our health can be found within our families and our communities. Our intimate relationships, our close friends, the relationship between children and their parents and siblings, and our broader social networks all can affect health and longevity for better — or worse.

Some of the broad mechanisms behind the connection between social relationships and better health are mapped out in one of the papers by a team at the University of Massachusetts, Amherst, and the University of California, Santa Barbara. They lay out how close connections to others improve our lives by relieving stress, expanding our perspectives, and making us feel understood and loved.

The flip side, of course, is also true: Our relationships also have the power to undermine our physical well-being. When our connections with others involve anger and negativity or social rejection, our health can suffer.

How Social Connections Reduce Stress

We’re social creatures by nature, and having a person or several people to rely on during tough times can, among other things, buffer psychological stress, which in turn can reduce our physiological stress responses. Having others to talk with during tough times can ease the wear and tear of the stress response on our cardiovascular systems (lowering blood pressure and pulse rate) and our hormone systems (reducing activity of the stress hormone cortisol).

Close ties can literally make difficulties less painful. Facing painful stimuli and daunting situations is easier with a friend or partner by your side. They also seem to boost our ability to recover emotionally from stressors.

The good news is that having friends can even help you cope with social rejection or a difficult marriage.

But even in times of calm, social ties are linked to better long-term health. One way is that social support provides opportunities for personal growth and potentially beneficial risk-taking, which includes everything from reaching for better job opportunities to eating more healthily and exercising. Recent studies have shown that couples with better relationships are more willing to compete for potentially rewarding outcomes, both in the lab and in real life — they’re also happier for it. And psychological well-being is well known to be linked to a longer life.

Having the support of close relationships is good for your health, and being a good friend is also good for you, but how you support others makes a difference. “To promote positive outcomes,” the team writes, “…support must be sensitive and responsive to the support recipient’s goals, needs, and preferences, leading the recipient to feel understood, validated, and cared for. Recent work suggests that, in some circumstances, the best support may be invisible — subtle, indirect, and unnoticed by the support recipient — because it allows individuals to obtain the benefits of support without the potential costs.”

Toxic Relationships and Loneliness

On the other side of the coin, people who are in bad relationships or who have few friends and little social support have worse health outcomes over time. “Interactions with close partners involving negativity or hostility — behaviors that often are unresponsive to partners’ needs — have been linked to disrupted physiological stress responses,” the authors write. Those with critical spouses have higher blood pressure, poorer immune responses, more inflammation and even slower wound healing. Similarly, social rejection has been linked to greater inflammation and greater cortisol reactivity.

The good news is that having friends can even help you cope with social rejection or a difficult marriage. It's not necessary, or important, to have many friends; having a few people you can confide in and rely on appears to be all it takes to reap the benefits of close relationships.

In recent years, the importance of mental health on physical well-being has come into the spotlight, and the stigma of addressing psychological issues is finally starting to dissolve. Loneliness is still something that’s not talked about quite as much. Hopefully, with all the new research coming out, this will change, and rather than brushing feelings of loneliness aside, people will reach out to others when they need it for all the good it can do.