Frequent social contact in midlife may reduce dementia risk, Whitehall II study analysis shows
Frequent social contact — regularly seeing friends and family — during midlife was associated with a lower likelihood of dementia diagnosis in later life, according to a recent study in PLOS Medicine. Being socially engaged may require greater activity in areas of the brain that contribute to language and memory, which in turn may account for better cognitive health, the authors noted.
Researchers at the University College London and INSERM in Paris analyzed data collected during the NIA-supported Whitehall II study from more than 10,000 British civil servants. Data were collected over 28 years, starting when the participants were middle aged. The participants responded to periodic questionnaires about social contact frequency and took tests of verbal memory, verbal fluency and reasoning. The researchers also obtained dementia diagnoses from the participants’ electronic health records.
The main outcome of the study was that adults who reported frequent social contact in middle age were less likely to receive a dementia diagnosis. The researchers also noted that this effect seemed to be stronger for participants who reported frequent interactions with friends than for those who reported social contact only with family members. Statistical analyses revealed that more frequent social contact at age 60 seemed to be associated with a greater reduction in subsequent dementia diagnosis than contact at either age 50 or age 70.
More frequent midlife social contact with friends, rather than relatives, was also linked with increased levels of cognitive performance. The researchers commented that the association between social contact frequency, reduced dementia risk and better cognitive performance may be a result of social contact improving cognitive reserve and thereby reducing dementia risk. Cognitive reserve may explain how some older adults can retain relatively normal thinking and memory abilities despite the presence of age-related brain changes.
Prior studies showed that people who have infrequent social connections may have a higher risk of dementia, but most of these studies were smaller in size and shorter in duration. In contrast, Whitehall II is one of the largest studies with the longest follow-up on the effects of social contact on dementia. Nevertheless, it is important to replicate these findings with other studies, especially in people who more closely reflect the diversity of the U.S. population.
This research was funded in part by NIA grant R01AG056477.
These activities relate to NIA’s AD+ADRD Research Implementation Milestone 1.F, “Support the inclusion of measures of AD-related phenotypes and environmental exposures in non-AD cohorts to enable new discovery research and to accelerate cross-validation of discoveries made in AD cohorts.”
Reference: Sommerlad A, et al. Association of social contact with dementia and cognition: 28-year follow-up of the Whitehall II cohort study. PLOS Medicine. 2019;16(8):e1002862.