Daily internet usage is associated with a decreased risk for dementia among older adults, according to study findings published in the Journal of the American Geriatrics Society.

Comparative studies have shown that older adults who engage in internet use have better cognitive performance, verbal reasoning, and memory, compared to their nonuser peers. However, longitudinal studies have only consisted of short follow-up periods, leaving the long-term benefits unexamined. Additionally, studies examining those who stop, start, or continue usage is still lacking. As such, researchers aimed to evaluate the long-term risk for dementia in those with regular internet usage and compare dementia risk in baseline internet usage to educational level, race/ethnicity, sex and generation, as well as the potential detrimental effects of excessive usage.

The researchers utilized the Health and Retirement Study (HRS), a nationally representative sample of older adults in the US. The included cohort consisted of adults who were dementia-free, aged 50-64.9, and self-completed baseline cognitive assessments. From 2002 onwards, HRS asked biennially about internet usage; participants were followed until the 2018 interview, for a maximum of 17.1 years. Those who satisfied age requirements, reported internet usage, and were of community residence were included in the study.

Primary outcome was incident dementia, which was identified by the biennial modified Telephone Interview for Cognitive Status (TICSm).

Being a regular internet user for longer periods in late adulthood was associated with delayed cognitive impairment, although further evidence is needed on potential adverse effects of excessive usage.

A total of 18,154 individuals were included in the study. Regular internet users accounted for 64.76% of users and nonregular users for 35.24%. Baseline internet users were found to have a lower prospective risk for dementia (1.54%), compared with their nonregular users (10.45%; 95%, CI, 7.96%-9.84%).


Cox proportional hazard models found time-to-dementia with regular internet usage to be 0.57%, compared with its counterpart of nonregular internet users (cause-specific hazard ratio [CHR], 0.57; 95% CI, 0.46–0.71).

Interestingly, the association between regular internet usage and risk for dementia did not vary significantly by educational level, race, ethnicity, sex, or generational cohort.

Of note, increasing cumulative daily internet usage by 2-hour increments was associated with a 21% decrease in dementia risk (95% CI, 13%–29%). A U-shaped relationship was found between daily hours of usage and dementia risk, with 0.1-2 hours showing the lowest risk, and 6.1 to 8 hours showing the highest estimate risk.

Limitations of the study included the preclusion of early-onset dementia, as well as not distinguishing between different online internet activities, which may further stratify risk.

The researchers noted, “Being a regular internet user for longer periods in late adulthood was associated with delayed cognitive impairment, although further evidence is needed on potential adverse effects of excessive usage.”

“Since a person’s online engagement may include a wide range of activities, future research may identify different patterns of internet usage associated with the cognitively healthy lifespan while being mindful of the potential side effects of excessive usage,” they concluded.

References:

Cho G, Betensky RA, Chang VW. Internet usage and the prospective risk of dementia: a population-based cohort study. J Am Geriatr Soc. Published online May 3, 2023. doi:10.1111/jgs.18394