New research, published in the journal PLOS One, shows that keeping strong friendships into old age may stave off mental decline.
The new study was carried out by researchers from the Cognitive Neurology and Alzheimer's Disease Center (CNADC) at Northwestern University Feinberg School of Medicine in Chicago, IL.
Emily Rogalski, associate professor at CNADC, is the senior author of the paper, and Amanda Cook, a clinical neuropsychology doctoral student in the laboratory of Rogalski and Sandra Weintraub, is the first author.
Rogalski and team examined the social network and cognitive abilities of a group of so-called SuperAgers – people who are in their 80s but have the mental agility of those in their 50s or 60s.
This is the first time that the social aspect of this population sample has been studied.
Studying the 'super' mentally sharp
Rogalski and her colleagues asked 31 SuperAgers and 19 age-matched controls to complete a 42-item questionnaire that enquired about their psychological well-being.
The questions spanned across six criteria: "autonomy, positive relations with others, environmental mastery, personal growth, purpose in life, and self-acceptance."
Participants were at least 80 years old, and their episodic memory was "at least as good" as that of their middle-aged peers.
Episodic memory is defined as "the capacity to recall specific experiences, as if one were to 'mentally time travel' to re-experience individual events."
SuperAgers have more friends
"While SuperAgers and their [age-matched] peers reported similarly high levels of psychological well-being across multiple dimensions," write the authors, "SuperAgers endorsed greater levels of positive social relationships."
More specifically, SuperAgers scored a median of 40 in the measure of social relations with others, whereas the controls only scored 36. As the senior researcher explains, this is a significant difference.
It could be the case, the authors write, that this difference is reflected in some neurological traits that have been observed in previous studies, as well.
These neurological features are "the greater thickness of the anterior cingulate gyrus and higher density of von Economo neurons" that researchers previously found in the brains of SuperAgers.
However, this is only a speculation, as the study is observational and cannot explain the mechanisms responsible for the findings.
Maintaining strong friendships is healthy
"You don't have the be the life of the party, but this study supports the theory that maintaining strong social networks seems to be linked to slower cognitive decline," says Rogalski.
"This finding is particularly exciting as a step toward understanding what factors underlie the preservation of cognitive ability in advanced age, particularly those that may be modifiable," adds Cook.
Rogalski also comments: "It's not as simple as saying if you have a strong social network, you'll never get Alzheimer's disease." Still, having friends may work as a great prevention factor.
"[If] there is a list of healthy choices one can make, such as eating a certain diet and not smoking, maintaining strong social networks may be an important one on that list. None of these things by [themselves guarantee] you don't get the disease, but they may still have health benefits."