Excessive TV Use Could Raise Risk of Dementia, PD, and Depression

Excessive TV watching was associated with increased risk of dementia, Parkinson disease (PD), and depression, while moderate computer use was associated with a decreased risk, according to a study recently published in the International Journal of Behavioral Nutrition and Physical Activity.

“Replacing different types of screen time with daily-life [physical activity (PA)] or structured exercise is associated with lower disease risk,” authors noted. “Our results support the potential of limiting different types of screen time and shifting to physical activity to mitigate disease risk.”

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Researchers included 473,184 participants who were free of dementia, PD, and depression at baseline. Screen time was self-reported by participants, and cox proportional hazards regression models were used to examine the association between different types of screen time and disease states. Researchers used linear regression models to examine the relationship between screen time and MRI biomarkers in the subgroup of participants. Participant physical activity levels were reported using a modified version of the International Physical Activity Questionnaire (IPAQ)

During follow-up, 6091 (1.29%) participants developed dementia, 3054 (0.65%) participants developed PD, 23632 (4.99%) participants developed depression, 1214 (0.26%) participants developed both dementia and depression multimorbidity, and 486 (0.10%) participants developed both PD and depression multimorbidity. Moderate computer use was negatively associated with white matter hyperintensity volume (β = -0.042; 95% CI -0.067, -0.017), and positively associated with hippocampal volume (β = 0.059; 95% CI 0.034, 0.084). In isotemporal substitution analyses, substituting TV or computer use with equal time of some sort of PA was associated with a lower risk of all 3 diseases, with strenuous sports showing the strongest benefit.

Researchers noted that, since participants self-reported screen time, recall bias could be a possible study limitation. Authors also noted that their sole focus on TV viewing and leisure time computer use without the inclusion of other sedentary behaviors like use of laptops, tablets, or smartphones could have also limited study results.

“More objective and device‐based measurements to access the screen behavior on weekdays and weekend days separately are needed in the future,” researchers concluded. 

Reference
Wu H, Gu Y, Du W, et al. Different types of screen time, physical activity, and incident dementia, Parkinson’s disease, depression and multimorbidity status. Int J Behav Nutr Phys Act. Published online November 3, 2023. doi.org/10.1186/s12966-023-01531-0