The internet has permeated almost every aspect of modern life, with research indicating an average individual spent roughly seven hours per day online in 2022. The figures varied significantly among countries, with South Africa leading in online usage at approximately 9.5 hours daily, contrasted by Japan at about four hours.
The widespread use of mobile phones has played a significant role in this upsurge. In 2012, mobile phones accounted for 10.88% of internet traffic, surging to 51.52% in 2023. Studies into the impact of this pervasive technology on brain health are ongoing.
The internet serves many functions for people across all age groups, ranging from leisure activities, such as gaming, to professional work. Over time, scientists have accumulated research probing the effect of internet usage on cognitive functions at various life stages. These studies present mixed findings. Some indicate potential mental health benefits, while others, particularly those focusing on excessive usage, warn of cognitive decline and related mental health concerns.
Many studies have investigated how behavioral elements like diet and exercise influence age-related cognitive function. Some researchers argue that contemporary societal factors such as internet usage warrant similar exploration. Pursuing this idea, a recent study published in the Journal of the American Geriatrics Society examines the correlation between moderate internet use and dementia risk among older adults.
| This post may interest those with a higher polygenic risk score for dementia. |
The Study
In brief, the study discovered a substantial decrease in dementia risk among regular internet users and observed a delay in cognitive impairment in individuals who maintained internet usage well into adulthood. This finding suggests that the internet could be a modifiable risk factor. Consequently, medical practitioners might eventually provide standard recommendations for internet usage among aging adults to enhance cognitive health and prevent dementia.
The researchers enlisted participants from the Health and Retirement Study (HRS), an extensive, longitudinal study focusing on US adults aged 50 or older. The study initially involved over 20,000 participants aged 50-64.9 years, all of whom were dementia-free at the outset. After accounting for various exclusion criteria, the final cohort comprised slightly over 18,000 adults.
Data collection on internet usage by the HRS began in 2002. The researchers conducted the initial cognitive assessments between 2002 and 2016, with follow-ups continuing until the 2018 interview, spanning a maximum of 16 years.
The cognitive assessment was administered via phone every two years to gauge dementia. During these interviews, the researchers inquired about the participants’ internet usage. They subsequently categorized the participants into regular and non-regular internet users. Additional data collected included the frequency of daily internet usage and demographic information.
Results
Among all participants, 65% were identified as internet users, leaving 35% as non-users. Regular internet usage was associated with roughly half the risk of dementia compared to non-usage. Additional statistical analyses demonstrated that factors such as education, race, ethnicity, sex, and generation did not influence these results.
Internet use duration also played a role. Participants reporting internet usage between 0.1 and 2 hours per day displayed a lower dementia risk compared to non-users. However, individuals spending 6 to 8 hours per day online showed an increased dementia risk, suggesting a need to balance internet usage to avoid adverse outcomes.
This study relied on an interview-based assessment to measure dementia, which the authors acknowledge has limitations. They recommend that future studies consider clinically diagnosed dementia cases. Other limitations included not factoring in the reverse effect (cognitive decline influencing internet usage) or differentiating between types of online activities.
In conclusion, the study discovered a considerable digital divide impacting the cognitive health of older adults. It’s among the first to employ an extended follow-up period and monitor internet usage post-baseline. The researchers call for further investigation to determine how long someone must use the internet regularly to yield cognitive benefits. They also suggest future studies discern between different internet activities and monitor for adverse effects of excessive use.
Citation
Cho G, Betensky RA, Chang VW. Internet usage and the prospective risk of dementia: A population-based cohort study. J Am Geriatr Soc. 2023 May 3. doi: 10.1111/jgs.18394. Epub ahead of print. PMID: 37132331.
