The Girl at the Desk

Desk Jobs Are Good for Your Brain?

The common wisdom and scientific evidence holds that physical activity helps your brain function better. Too much sitting time supposedly gets in the way of good cognitive function But now, a new observational study suggests that sedentary desk jobs might be good for your brain. What gives?

A Counter-Intuitive Observational Study

The first thing to know about this study is that it’s observational. Thus, all we can glean from it are association. Not causal relationships. The authors followed 8,585 men and women for two decades. They measured cognitive function and collected self-reports on physical activity levels – both at work and leisure.

They found that physical inactivity at work predicted less decline in brain function. However, inactivity in leisure time had precisely the opposite relationship. Being less active at leisure predicted more cognitive decline. Over time, people with manual labor jobs did worse. People with desk jobs did better.

Of course, this goes against the conventional wisdom about sitting and physical activity. So Cambridge issued a press release and got lots of attention. “Desk jobs may offer protection against poor cognition,” it said.

Not So Fast

These investigators are raising some good questions. But they’re dancing around a claim of causality when all they have is a correlation. And on top of that, they have a number of limitations in this study.

First and foremost is residual confounding. As the authors say, they are lacking a number of variables that make this issue especially important:

Another limitation is the inability to control for other early-life indicators such as prior intelligence, family social-economic status and parental education, which are known determinants of cognitive function, but were not available in this cohort.

Also, the study suffers the limitation of self-reported physical activity. It’s not especially reliable. People misremember how active they’ve been. And the memory lapses can introduce systematic bias.

Desks for Brains or Brains for Desks?

So the question remains. Are desk jobs good for your brain? Maybe. Or maybe good brains are helpful in desk jobs. Or more likely, the truth is a bit more complicated than Cambridge could wedge into a press release.

In any event, sitting for hours on end without a break is definitely not good for your body or your brain. So get up and move.

Click here for the study and here for the press release. For a sample of the stories written about it, click here, here, and here.

The Girl at the Desk, painting by Kuzma Petrov-Vodkin / WikiArt

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July 10, 2020