Strong, steady friendships may benefit physiological health, study shows

(CNN) — Good friends and good physical health may be even more closely linked than previously thought, new research has found.

Researchers discovered that positive social experiences impact not only a person’s stress level and ability to cope, but also markers of physical health, according to a study published Monday in the journal Society for Personality and Social Psychology.

The study followed more than 4,000 people over three weeks as they completed check-ins every three days on their smartphones or smartwatches regarding their positive and negative experiences with their closest social relationships, as well as assessments of their blood pressure, heart rate, stress and coping.

Having more positive experiences in social relationships was generally associated with better coping, lower stress and lower systolic blood pressure, or spikes in blood pressure under stress, according to the study.

But having social relationships which bounce between good and bad often can be unhelpful. When there is a lot of volatility, the negative experiences seemed to have a bigger impact on a person than the positive, said lead study author Brian Don of the University of Auckland.

“Both positive and negative experiences in our relationships contribute to our daily stress, coping, and physiology,” Don said in a statement. “Additionally, it’s not just how we feel about our relationships overall that matters; the up’s and downs are important too.”

The results are not surprising, given that previous studies have also documented a link between healthy relationships and healthier bodies, said Dr. Kathleen Mullan Harris, a professor of sociology at the University of North Carolina at Chapel Hill. Harris was not involved in the study.

But seeing how friendships affect specific aspects of physical health does add to the scientific understanding of the connection, she said.

The research, which took place from 2019 to the end of 2021, may also offer insight into the impacts of the Covid-19 pandemic, which put strain on social relationships for many people, Don said.

“Because the COVID-19 pandemic has created considerable strain, turbulence, and variability in people’s relationships, it may indirectly alter stress, coping, and physiology in daily life, all of which have important implications for physical well-being,” he added.

Do good friendships lead to better health?

It is important to remember that the study cannot prove that good relationships cause better health, Don said.

But it does show that physical health and social relationships are often intertwined, he said.

And the association can also work the other way, Harris said.

“People who are in better health often have better relationships with people, because they’re not moody, they’re not grouchy, they’re not in pain, they don’t have worries,” she said.

Don hopes that future studies expand the areas that are investigated.

“It would be useful to examine other physiological states, such as neuroendocrine or sympathetic nervous system responses as outcomes of daily positive and negative relationship experiences, which may reveal different patterns of associations,” he said.

Making better relationships

If hearing the importance of good social relationships makes you lament that you might not have enough, you aren’t alone, said Adam Smiley Poswolsky, workplace belonging expert and author of “Friendship in the Age of Loneliness.”

Many people may feel lonely and want closer connections, but the prospect of making new friendships — or strengthening existing ones — can be daunting, Poswolsky said.

“It’s intimidating to think about friendship in adulthood, and often overwhelm keeps us from even trying,” he said.

His suggestion? Start small. Text a friend that you haven’t talked to in a long time, commit to meeting one new person a month, host a dinner party, or join a class.

“If you do just one thing, make a list of five people in your life that you care about, and give one of them a phone call,” Poswolsky added. “The most remarkable friendships often begin with tiniest moments of connection.”

Remember that you likely won’t form a strong connection overnight, he added.

Research shows that it takes 90 hours of time together to consider someone a friend and more than 200 hours to consider them a close friend that you have an emotional connection with, he said.

“In our busy world, we need to put our friendship on the calendar, and commit to recurring activities,” Poswolsky said.

But studies also reveal that it isn’t just about having relationships — the quality matters.

There might not be just one definition of a good friendship, but most strong relationships share some similar qualities, he said.

They tend to prioritize laughter, joy, excitement, courage, vulnerability, affirmation and a lack of judgment, Poswolsky said. And good friendships are often two people helping each other become better versions of themselves, he added.

“Even when — especially when — their friend is struggling or going through something hard,” Poswolsky said. “You know someone is a true friend when they have your back when you’re sick, when you lose your job, when you make a mistake, when you’re going through a break-up, when you’re stressed, when you’re sad.”