Standing desks—and even biking desks—are a response to a growing body of studies showing that a sedentary lifestyle poses a number of health risks. Regular physical activity appears to offer some degree of protection against a variety of problems, both physical and mental, and many results suggest that it is not Olympic-level training. Just walking around the apartment a few times a day helps.
Now, a team of researchers has turned to the opposite question: Are all types of inactivity the same? The answer is probably not. While the details depend on the health issues involved, there is likely to be some good news for those reading this, in that computer use appears to be somewhat protective against dementia.
get out of your chair
The physical risks associated with inactivity are generally associated with reduced heart health, either directly or through obesity. Even a small amount of physical activity appears to be able to limit these effects, although increased exercise generally seems to be even better (details vary depending on studies and the exact risks investigated. ).
But exercise also improves mental health. It can be an effective treatment for depression and other disorders, and helps to reverse some of the unfortunate effects of aging. “Exercise and physical activity have shown promise in reducing cognitive decline, structural brain atrophy, and dementia risk in older adults,” the authors write, citing work done in other studies.
One of the oddities of some of the studies noted in the new study is that many of them use hours spent watching television as a stand-in for idle time. While this may have been true a few decades ago, we’ve diversified our inaction a lot since then, with computers and mobile devices offering new ways to feel like you’re doing something without needing to do anything. .
Therefore, the researchers decided to look at this in more detail and tackle some related questions. Their study design separated computer use and TV viewing, and looked at how each affected the onset of mental problems associated with aging. It also examined whether physical activity could influence the association between sedentary behavior and problems associated with aging.
To do this, the researchers took advantage of the UK Biobank, a large database that links the demographics and health outcomes unknown to hundreds of thousands of UK citizens. For this work, the team excluded people under the age of 60 and focused on about 75,000 people who filled in detailed information about their activity levels and leisure activities.
not good but better
Before we get into the results, a small reminder: Work focused on the impact of sedentary behavior on mental issues. Physical health issues were not examined – it is possible for something that looks relatively good in this analysis to be negative overall once physical issues are taken into account.
That way, what did they see? With controls for age and gender, time spent watching TV was associated with an increased risk of dementia (an hazard ratio of 1.3, meaning they were 1.3 times more likely to be diagnosed with signs of dementia). Physical activity greatly reduced the risks. Conversely, computer use reduced the risk a bit further, leaving the risk ratio at 0.8.
The same trend occurred when the researchers divided the group into thirds and compared high, medium and low TV viewing and computer use. Controlling for additional factors such as diet, alcohol use and obesity also did not change the results.
Although the effect of physical activity was modest, the researchers tested whether it could reverse some of the problems associated with high TV viewing or low computer use. High levels of exercise have a somewhat protective effect, but it is modest.
mental reserve
Overall, the results suggest that we need to differentiate the way we think about problems associated with sedentary activity. In terms of physical health, any form of inactivity can be roughly equivalent. But with regard to mental issues, how do you spend your inactivity – some means of being a couch potato involve passive consumption, and others involve a great deal of mental activity.
In this sense, the results fit neatly into a large body of research that indicates that staying mentally active may offer a degree of protection against dementia. Things like reading and playing vocabulary games generally reduce dementia risk, and the benefits seem to build up even when people are relatively young. So, there’s some reason not to be surprised by this general result.
That said, there are still many reasons to exercise caution. Among other potential issues, the researchers note that activity levels at only one point in the participants’ history were examined and self-reported, which tends to be less accurate. It is also important to recognize that computer time will involve a wide range of activities, some significantly more involved than others. So there’s still some work to be done here. But the next time someone yells at you for wasting time reading Ars, you can tell them you’re protecting your mental health.
PNAS2022. DOI: 10.1073/pnas.2206931119 (About DOI).
(This story has not been edited by seemayo staff and is published from a rss feed)