Impact of Internet Use on Cognitive Decline in Middle-Aged and Older Adults in China: Longitudinal Observational Study

Background: Given that cognitive decline lacks effective treatment options and has severe implications for healthy aging, internet use may achieve nonpharmacological relief of cognitive decline through cognitive stimulation and social engagement. Objective: This longitudinal study aimed to investigate the relationship between the diversity, frequency, and type of internet use and cognitive decline, and to provide theoretical support and suggestions for mitigating cognitive decline in middle-aged and older adults. Methods: Data were obtained from a total of 10,532 survey respondents from the China Family Panel Studies database from wave 3 (2014) and wave 5 (2018) of the survey. Cognitive function was measured using vocabulary tests, and internet use was categorized into five aspects: study, work, socializing, entertainment, and commercial-related activities. Associations between the diversity, frequency, and type of internet use and cognitive decline were estimated by controlling for demographic variables and health status risk factors through fixed-effects models. Results: After controlling for demographic and health status risk factors, the type and frequency of internet use were found to be associated with cognitive functioning during the subsequent 4-year period, and different types of internet use had different effects on cognitive decline. Frequency of internet use of at least once a week for study (beta=0.620, 95% CI 0.061 to 1.180; P=.04), work (beta=0.896, 95% CI 0.271 to 1.520; P=.01), and entertainment (beta=0.385, 95% CI -0.008 to 0.778; P=.06), as well as less than once a week for social purposes (beta=0.860, 95% CI 0.074 to 1.650; P=.06), were associated with better cognitive function. Frequency of internet use of less than once a week for commercial-related activities (beta=-0.906, 95% CI -1.480 to -0.337; P=.005) was associated with poorer cognitive function. Using the internet for more than one type of activity (beta=0.458, 95% CI 0.065 to 0.850; P=.03) and at least once a week (beta=0.436, 95% CI 0.066 to 0.806; P=.02) was associated with better cognitive function. Conclusions: This study shows that breadth and depth of internet use are positively associated with cognitive function and that different types of internet use have different roles in cognitive decline. The importance of the internet as a nonpharmacological intervention pathway for cognitive decline is emphasized. Future research could explore specific mechanisms of influence.