" " Having childhood friends is good for your later physical health. wundervisuals/Getty Images

Remember your best friend from childhood? Apart from providing fun and companionship, he just might help you to live longer and healthier. A recent study published in on March 18, 2018 in the journal Psychological Science shows that boys who spent a lot of time with friends often have lower blood pressure (BP) and lower body mass index (BMI) numbers by the time they hit their 30s. In short, those playground buddies make for healthier men, big news at a time when about 54 of 100,000 deaths worldwide is attributable to obesity and cardiovascular disease is America's No. 1 killer, responsible for one out of every three deaths.

The study linked positive, socially active children with improved health later. Why's that? Possibly because kids who have stronger social networks simply have less exposure to the kinds of variables (like stress) that ultimately contribute to cardiovascular meltdowns, such as heart attack or stroke, in adulthood. Less stress and more happiness, it seems, reverberate throughout life.



"What the study shows is that men who spent more time with their friends on average during childhood and adolescence tend to have lower BMI and BP in young adulthood (~ age 32)," says study co-author Jenny Cundiff, an associate professor with the Department of Psychological Sciences at Texas Tech University in an email interview.

The researchers examined data from the Pittsburgh Youth Study (PYS) which started in 1987, and followed 267 boys from approximately age 6 until they turned 16. The scientists noted the amount of time the boys spent interacting with their friends, whether playing or fighting, both as small children and later in adolescence. The PYS is what's called a longitudinal study, one that recorded many observations of the same variables over a period of time.

Flash forward nearly two decades when the subjects were recontacted: The adults who experienced higher levels of childhood peer interaction now had healthier BMI levels and cardiovascular function compared to the adults who lacked childhood social support. This pattern held true regardless of whether the subjects were black or white.

Cundiff emphasizes that the study does not establish causation. "However, because it is a well-controlled longitudinal study in a racially diverse sample, 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 (e.g., extroversion), physical health in childhood, and childhood socioeconomic resources."

Americans expect men to be honest and financially successful — but the culture does not traditionally place high value on male social bonding. In fact, several recent articles have talked about how lonely American men are. Cundiff's study emphasized male behavior and health because the PYS study only recruited males.

So, what about girls and later female physical well-being? "There are very few previous longitudinal studies on the topic, but those previous studies that included women have actually found a stronger link [between close relationships and health] for women than men (e.g., Ehrlich, Hoyt, Sumner, McDade, & Adam, 2015). Of course, there are also many differences between those studies and ours."

Cundiff isn't finished exploring the intersection of childhood interactions and its consequences. She plans to continue to look at relationships early in life as a precursor to cardiovascular risk later in life.