Maintaining strong social networks with positive, warm and trusting friendships in old age might be key to slowing down age-related decline in memory and brain functioning, researchers say.

The findings showed that superagers -- who are 80 years and older -- who have cognitive ability at least as good as people in their 50s or 60s can have more satisfying, high-quality relationships compared to their cognitively average, same-age peers."This study supports the theory that maintaining strong social networks seems to be linked to slower cognitive decline," said Emily Rogalski, Associate Professor at the Northwestern University in the US."The study 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," added Amanda Cook, doctoral student at the varsity.

Previous studies has shown psychological well-being in older age to be associated with reduced risk of developing Alzheimer's dementia."It's not as simple as saying if you have a strong social network, you'll never get Alzheimer's disease," Rogalski said. "But 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," Rogalski noted.For the study, published in the journal PLOS ONE, the participants answered a 42-item questionnaire called the Ryff Psychological Well-Being Scale, which is a widely used to measure of psychological well-being. 

The scale examines six aspects of psychological well-being: autonomy, positive relations with others, environmental mastery, personal growth, purpose in life and self-acceptance. Superagers scored a median overall score of 40 in positive relations with others while the control group scored 36 -- a significant difference, Rogalski said.