TOPLINE:
Excessive television-watching is tied to an increased risk for dementia, Parkinson's disease (PD), and depression, whereas a limited amount of daily computer use that is not work-related is linked to a lower risk for dementia.
METHODOLOGY:
- Investigators analyzed data on 473,184 people aged 39-72 years from the UK Biobank who were enrolled from 2006 to 2010 and followed until a diagnosis of dementia, PD, depression, death, or study end (2018 for Wales residents; 2021 for residents of England and Scotland).
- Participants reported on the number of hours they spent outside of work exercising, watching television, and using the computer.
- MRI was conducted to determine participants' brain volume.
TAKEAWAY:
- During the study, 6096 people developed dementia, 3000 developed PD, 23,600 developed depression, 1200 developed dementia and depression, and 486 developed PD and depression.
- Compared with those who watched TV for under 1 hour per day, those who reported watching 4 or more hours per day had a 28% higher risk for dementia (adjusted hazard ratio [aHR], 1.28; 95% CI, 1.17-1.39), a 35% higher risk for depression, (aHR, 1.35; 95% CI, 1.29-1.40) and a 16% greater risk for PD (aHR, 1.16; 95% CI, 1.03-1.29).
- However, moderate computer use outside of work seemed somewhat protective. Participants who used the computer for 30-60 minutes per day had lower risks for dementia (aHR, 0.68; 95% CI, 0.64-0.72), PD, (aHR, 0.86; 95% CI, 0.79-0.93), and depression (aHR, 0.85; 95% CI, 0.83-0.88) compared with those who reported the lowest levels of computer usage.
- Replacing 30 minutes per day of computer time with an equal amount of structured exercise was associated with decreased risk for dementia (aHR, 0.74; 95% CI, 0.85-0.95) and PD (aHR, 0.84; 95% CI, 0.78-0.90).
IN PRACTICE:
The association between extended periods of TV use and higher risk for PD and dementia could be explained by a lack of activity, the authors note. They add that sedentary behavior is, "associated with biomarkers of low-grade inflammation and changes in inflammation markers that could initiate and or worsen neuroinflammation and contribute to neurodegeneration."
SOURCE:
Hanzhang Wu, PhD, of Tianjin University of Traditional Medicine in Tianjin, China, led the study, which was published online on November 3, 2023 in the International Journal of Behavioral Nutrition and Physical Activity.
LIMITATIONS:
Screen behaviors were assessed using self-report measures, which is subject to recall bias. Also, there may have been variables confounding the findings for which investigators did not account.
DISCLOSURES:
The study was funded by the National Natural Science Foundation of China, the Tianjin Major Public Health Science and Technology Project, the National Health Commission of China, the Food Science and Technology Foundation of Chinese Institute of Food Science and Technology, the China Cohort Consortium, and the Chinese Nutrition Society Nutrition Research Foundation—DSM Research Fund, China. There were no disclosures reported.
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