Computers vs. TV: Which is less likely to promote dementia?

A growing body of studies shows that a sedentary lifestyle can lead to health risks. Regular physical activity appears to give a degree of protection from various problems, both physical and mental, and many results show that this doesn't have to be Olympic-level training. A few times a day, you can simply walk around the apartment.

A group of researchers looked at the question of whether all forms of activity are equally inactive. The answer may not be correct. In that computer use appears to be protective against dementia, there is some good news for people reading this.

Get off your chair

Lower cardiovascular health can be linked to the physical risks associated with being inactive. Increased exercise seems to be even better than a small amount of physical activity at limiting these impacts.

Mental health can be improved by exercising. It can be an effective therapy for depression and other disorders, as well as helping to stave off some of the effects of aging. The authors say that exercise and physical activity have shown promise in reducing cognitive decline, structural brain atrophy, and dementia risk in older adults.

Several of the studies noted in the new one used hours of watching the television as a stand-in for inactive time. Since that may have been true a few decades back, we've diversified our activity, with computers and mobile devices giving us new ways of feeling like we're doing something without the need to do anything.

The researchers decided to take a more detailed look at this. The design of the study separated computer use and TV viewing and looked at how each affected the mental health of older people. It looked at the relationship between sedentary behavior and aging-related problems.

The UK Biobank is a large database of health outcomes and demographic information for hundreds of thousands of UK citizens. The team excluded people under the age of 60 years old and focused the work on people who had filled out detailed information about their leisure activities.

Not good, but better

The work focused on the effect of sedentary behavior on mental issues. It is possible for something that looks good in this analysis to be an overall negative once physical issues are included.

What did they see? With age and gender controlled for, time spent watching TV was associated with an increased risk of dementia. The risks were reduced slightly by physical activity. The computer use lowered the risk more than the other way around.

When the researchers divided the group into thirds, the trend stayed the same. The outcome was not changed by controlling for diet, alcohol use, and obese people.

Some of the problems associated with high TV viewing or low computer use may be mitigated by physical activity. It appears that high levels of exercise have a protective effect.

Mental reserve

The results show that we need to separate how we think about sedentary activity. Any type of activity is equivalent to physical health. Some means of being a couch potato involve passive consumption and others involve more mental activity.

The results fit nicely into a large body of research that shows that mentally active people are less likely to develop dementia. The benefits of reading and playing vocabulary games seem to build up even if the reading happens when people are younger. There are reasons not to be surprised by this outcome.

There are many reasons to be cautious. According to the researchers, activity levels were only checked at one point in the participants' history and were self- reported, which tends to be less accurate It is important to know that computer time will include a wide range of activities, some more involved than others. There are still some things to be done here. You can tell someone you're protecting your mental health if they yell at you for wasting time.

Pnas in 2022. About DOIs can be found at 10.1073/pnas. 2206931119.