This analysis of 13 longitudinal cohort studies from multiple continents with follow-ups as long as 15 years, was the largest of its kind, evaluating the association between social connections and cognition. The major finding is that having good social connections is associated with a slower decline in both global cognition as well as declines in memory and language. A slower annual decline was linked to being married or in a relationship, living with one or more people, and never feeling lonely. Interactions with community groups as well as with family and friends were also associated with slower memory decline.
Although this study does not reveal mechanisms, it does support the hypothesis that having good social connections structure and quality (i.e., being in relationships and not feeling lonely) may increase “cognitive reserve” by reducing stress, while interactions with family, friends, and community members provide cognitive stimulation and the opportunity to practice memory and language skills. This analysis supports previous research indicating that our social ties and relationships not only enrich our lives but help to keep us young, providing another reason to enjoy the holidays together.