University of North Carolina at Chapel Hill
The more social ties people have at an early age, the better their health is at the beginnings and ends of their lives, according to a new study from the University of North Carolina at Chapel Hill.
The study is the
first to definitively link social relationships with concrete measures of
physical well-being such as abdominal obesity, inflammation, and high blood
pressure, all of which can lead to long-term health problems, including heart
disease, stroke and cancer.
"Based on these findings, it should be as important to
encourage adolescents and young adults to build broad social relationships and
social skills for interacting with others as it is to eat healthy and be
physically active," said Kathleen Mullan Harris, James Haar Distinguished
Professor at UNC-Chapel Hill and faculty fellow at the Carolina Population
Center (CPC).
The study, published in the Proceedings of the National Academy of Sciences, builds on previous research that shows that aging adults live longer if they have more social connections. It not only provides new insights into the biological mechanisms that prolong life but also shows how social relationships reduce health risk in each stage of life.
Specifically, the team found that the sheer size of a person's
social network was important for health in early and late adulthood. In
adolescence, that is, social isolation increased risk of inflammation by the
same amount as physical inactivity while social integration protected against
abdominal obesity.
In old age, social isolation was actually more harmful to
health than diabetes on developing and controlling hypertension.
In middle adulthood, it wasn't the number of social connections
that mattered, but what those connections provided in terms of social support
or strain.
"The relationship between health and the degree to which people
are integrated in large social networks is strongest at the beginning and at
the end of life, and not so important in middle adulthood, when the quality,
not the quantity, of social relationships matters," Harris said.
Harris and her team drew on data from four nationally
representative surveys of the U.S. population that, together, covered the
lifespan from adolescence to old age.
They evaluated three dimensions of social
relationships: social integration, social support and social strain.
They then
studied how individual's social relationships were associated with four markers
shown to be key markers for mortality risk: blood pressure, waist circumference,
body mass index and circulating levels of C-reactive protein, which is a
measure of systemic inflammation.
One of the four nationally representative surveys was part of
The National Longitudinal Study of Adolescent to Adult Health, or Add Health, the
largest, most comprehensive data researchers use to study how social
relationships, behavior, environment and biology interact to shape health in
adolescence and influence well-being throughout adulthood.
"We studied the interplay between social relationships,
behavioral factors and physiological dysregulation that, over time, lead to
chronic diseases of aging -- cancer being a prominent example,"
Yang
Claire Yang, a professor at UNC-Chapel Hill, CPC fellow and a member of the
Lineberger Comprehensive Cancer Center. "Our analysis makes it clear that
doctors, clinicians, and other health workers should redouble their efforts to
help the public understand how important strong social bonds are throughout the
course of all of our lives."