Being socially active can stave off dementia’s advance

Seeking out social situations and participating in activities that involve interacting with others and forming connections help delay the onset of dementia by 5 years, as reported in a study.

In a cohort of older adults who participated in the Rush Memory and Aging Project, those who were most socially active had a 38-percent lower risk of dementia (hazard ratio [HR], 0.62, 95 percent confidence interval [CI], 0.51–0.75) and a 21-percent lower risk of mild cognitive impairment (MCI) (HR, 0.79, 95 percent CI, 0.66–0.94). [Alzheimers Dement 2025;21:e14316]

The median age at dementia diagnosis was 93.2 years among participants in the top tertile of social activity, 90.7 years among those in the middle tertile, and 88.5 years among those in the bottom tertile. Meanwhile, MCI diagnosis among the least socially active occurred an average of 1 year earlier relative to those with moderate social activity and 3 years earlier relative to those with the highest social activity (median age, 78.4 vs 79.7 and 81.2 years, respectively).

The analysis included 1,923 older adults, of which 545 and 695 received a diagnosis of dementia and MCI, respectively, over a mean follow-up of 6.7 years.

“This study is a follow up on previous papers from our group showing that social activity is related to less cognitive decline in older adults,” said senior study author Prof Bryan James from Rush University Medical Center, Chicago in Illinois, US.

“Estimating differences in age of dementia/MCI onset allows us to more directly link greater social activity to potential health and economic benefits. For example, a 5-year delay in dementia onset has been estimated to yield an additional 3 years of life and over USD 500,000 of lifetime healthcare savings for each person who would eventually develop dementia,” James added. [Forum Health Econ Policy 2015;18:25-39]

He stressed that the findings help demonstrate the public health relevance of social activity, which has strong potential to reduce dementia at the community level.

The power of social connection

“Social engagement is a multidimensional construct encompassing interrelated but distinct domains, including structural aspects (eg, social activity, social network size, marital status), functional aspects (eg, social support), and subjective psychosocial experience (eg, loneliness),” James said. [BMC Public Health 2022;22:1-14; Exp Aging Res 2009;35:45-60]

He noted that while the exact mechanisms are unclear, several theories suggest that social engagement may enhance cognitive resilience through processes such as synaptogenesis and neurogenesis. These processes can promote cognitive resilience that buffers against the accumulation of Alzheimer's disease or other dementia-related neurodegenerative pathologies. [J Int Neuropsychol Soc 2011;17:998-1005; Lancet Neurol 2004;3:343-353; Psychol Med 2006;36:1065-1073]

“Social activity is likely to reduce stress, which interferes with the hypothalamic pituitary–adrenal axis and leads to loss of hippocampal neurons,” James said. [Alzheimer Dis Assoc Disord 2012;26:260-266]

It is also possible that social activity may confer beneficial effects on dementia risk by increasing physical activity or alleviating loneliness, he added. [Lancet Neurol 2020;19:533-543]