According to new research, watching television (TV) is associated with a rise in the risk of dementia, while using a computer is linked with a decrease in dementia risk. This prospective cohort study was performed to understand the impact of viewing TV and using computers on dementia risk. No matter how much physical exercise a person does, the link between these behaviours and dementia remains robust.

Watching TV and using a computer have both been associated with an elevated risk of chronic illness and death, but exercise and physical activity have been found to benefit older persons by lowering the risk of dementia, structural brain atrophy, and cognitive impairment.  It is not the sitting portion of sedentary behaviour  that may influence dementia, but rather what people do when sitting.

Utilizing data from the Biobank, this study was carried out. A total of 146,651 people were included following the exclusion of people under the age of 60, those with dementia at the initiation of the follow-up, and those with incomplete data. The participants were tracked from their initial visit until they were last admitted to the hospital, lost to follow-up, dead, or diagnosed with dementia.  Time spent viewing TV was associated with an elevated risk of incident dementia (Hazard ratio [HR] = 1.31), but computer use was related to a lower risk of incident dementia (HR = 0.80).

The connection between TV usage and dementia risk raised in those who used it the most in comparison with those who used it the least (HR = 1.28). Likewise, the association between computer use and reduced dementia risk elevated with higher use. Both high and medium computer time was linked to a lower risk of incident dementia (HR = 0.76 and 0.70, respectively).

In this study, high TV usage was defined as ≥ 4 hours/day, and computer use, which included leisure use but not work use, showed positive effects on dementia risk after just 30 minutes. After the researchers made adjustments for demographic, health, and lifestyle factors such as time spent on exercise, sleeping, obesity, alcohol use, smoking status, diet scores, level of education, body mass index, and kind of employment, these results remained significant.

One potential reason for the different effects on dementia risk in the two activities is that sitting down to watch TV is related to uniquely low levels of muscle activity and energy expenditure, compared with sitting to use a computer. Large portions of the cortex are utilized when doing cognitive activity using a computer, but just only a tiny portion of the brain is likely to be active while watching TV.

Physical activity is advisable. But, if the choice is sedentary activities, then active cognitive activities like computer use are much better when compared to TV viewing.  The results of the current study demonstrated consistency with prior research that showed that the type of sedentary behavior matters. To sum up, TV viewing is linked to mortality and poor cardiometabolic indicators, whereas computer use is not. Future research is required to measure sedentary behavior and physical activity using objective techniques.