That’s the takeaway message from an analysis of non-identifiable patient data recently reported in this article:

Too much TV watching correlated with higher rates of dementia, depression, and PD

However, the study did find that some computer screen time had a neuroprotective effect. (This blog’s  author’s note: It would not be a bad idea to set a timer to remind yourself to get up every hour or so and get up, stand up, and dance to a little Bob Marley music for a minute or two, or three).

Methods

• 473,184 participants initially free of dementia, PD, and depression from UK Biobank, as well as 39,652 participants who had magnetic resonance imaging (MRI) data
• Self-reported screen time exposure variables included
  • TV viewing and
  • computer use
• Regression models were used to estimate the association between different types of screen time and
  • Incidence of dementia,
  • Parkinson’s disease,
  • depression, and
  • Multimorbidity status.
• Multiple linear regression models were used to assess the linear relationship between different types of screen time and MRI biomarkers in a subgroup of participants.

Multimorbidity was defined as two or more diagnoses of chronic diseases occurring simultaneously in an individual.

During the study time frame,

• 6,091 (1.29%) participants developed dementia
• 23,632 (4.99%) participants developed depression,
• 1,214 (0.26%) participants developed both dementia and depression,
• 486 (0.10%) participants developed both PD and depression

Participants

•  Highest TV viewing time were
  • Older,
  • Typically male,
  • Higher body mass index (BMI),
  • Lower Physical Activity (PA) and
  • More likely  previous or current smokers.

Risk for dementia and depression increased substantially among those with both low PA and highest TV viewing time.

The main novel finding of this study is that TV viewing time was positively associated with an increased risk of dementia, PD, depression and their multimorbidity status. Moderate computer using time (i.e., approximately 0.5–1 h/day) is associated with a lower risk of dementia, PD, and depression.  

Longitudinal analysis and eliminating cases of depression, dementia, and PD that were diagnosed within the first three years are the strengths of the study. Self-reports on the amount of screen time by participants is a weakness.

In conclusion:

 computer using was U-shaped associated with risk of dementia, PD, depression and their multimorbidity status, while TV viewing was associated with an increased risk. And different screen time may affect diseases risk through its association with brain structures. Although associations between different types of screen time and diseases are not strongly attenuated with different levels of PA. Replacing different types of screen time with daily-life PA or structured exercise is associated with lower disease risk. Our results support the potential of limiting different types of screen time and shifting to physical activity to mitigate disease risk.

And this person with PD has spent too many hours in front of the computer screen writing this up, so I will follow their advice and engage in some PA.

Citation:

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 20, 130 (2023). https://doi.org/10.1186/s12966-023-01531-0

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