Remember that childhood friend you used to hang out with till it got so late your parents had to drag you back to the house? Or that high school confidante you'd spend ages with chatting on the phone? The comfort these friends brought you then might extend well into your adulthood and keep you healthy in the long-term, says a new study.

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Your childhood 'bestie' may have a surprisingly protective effect on your health as an adult.

"[W]hen you're a kid," comedian Jerry Seinfeld said, in what is now a classic episode of his show, "you can be friends with anybody,"

He goes on. "Remember when you were a little kid what were the qualifications? If someone's in front of my house now, that's my friend; they're my friend. That's it! Are you a grown up? No? Great! Come on in! Jump up and down on my bed!"

Making "best friends" was also easy as a kid, continues Seinfeld. "[I]f you have anything in common at all: 'You like cherry soda?' I like cherry soda! We'll be best friends!"

However, making new companions as adults is not as easy. As an adult, you probably aren't that interested in new "BFFs" — or, in Seinfeld's words, "You're not interviewing, you're not looking at any new people, you're not interested in seeing any applications."

The good news, however — coming from a study recently published in the journal Psychological Science — is that the friendships we made so easily in childhood have health benefits that can carry over well into our adulthood.

In fact, the study — carried out by Jenny M. Cundiff, at Texas Tech University in Lubbock, and Karen A. Matthews, at the University of Pittsburgh in Pennsylvania — suggests that the more time that you spent hanging out with your best buddies as a kid, the likelier you are to have a healthy weight and blood pressure as an adult.

Healthier weight and blood pressure

It's a fact that friendships boost your health and well-being. In adulthood, having more friends correlates with a lower risk of heart disease and hypertension. But do the benefits of your childhood friends last into adulthood?

This is what the researchers wanted to find out, so they analyzed data from a large longitudinal study of 267 adults whose social lives were monitored between the ages of 6 and 16. Of all the study participants, around 56 percent were black and about 41 percent were white.

The study also looked at personality traits such as introversion and extraversion in both childhood and adulthood, as well as physical health and socioeconomic status.

The researchers found that adults who used to spend a lot of time with friends as young boys had lower blood pressure levels and body mass index (BMI) at the age of 32.

After accounting for potential confounders, this association was still strong and evident over a 16-year period.

Cundiff comments on the strength of the findings, saying, "Although this wasn't an experiment, it was a well-controlled longitudinal study in a racially diverse sample."

"[S]o," she continues, "it provides a strong clue that being socially integrated early in life is good for our health independent of a number of other factors such as personality, weight in childhood, and the family's social status in childhood," the psychologist explains.

"These findings suggest that our early social lives may have a small protective influence on our physical health in adulthood, and it's not just our caregivers or financial circumstances, but also our friends who may be health protective."

Jenny M. Cundiff

To summarize, if a common preference for cherry soda isn't enough to make new friends anymore, don't worry; your childhood friends who used to jump on your bed are, in some ways, still looking out for you.