Some health messages such as “sitting is the new smoking” spread not because they’re true, but because they’re catchy and tweetable. And when promoting a new health scare, comparisons are always useful for raising alarm. “Sitting is more dangerous than smoking, kills more people than HIV and is more treacherous than parachuting. We are sitting ourselves to death,” said one expert in the Los Angeles Times.

It’s a great quote to show to worried family members if you want to go parachuting. But otherwise, this sort of thing can make it seem pointless to even try to live a healthy lifestyle. You work hard to quit smoking only to learn your office chair will kill you.

Matt Buman, health researcher at Arizona State University, said he and some colleagues decided to try to put “sitting is the new smoking” to the test. He told me he agrees with the evidence that sitting too much is a health hazard. There have been studies showing that people who spend more time sitting are more likely to die earlier from various chronic diseases than are people who sit less. But is sitting really as bad as or worse than smoking?

“We looked at the literature and compared the effect sitting has on various health outcomes, including early cardiovascular death, diabetes, and some cancers, and compared the effect smoking has,” he said. “Smoking is much worse.” They published their findings in the American Journal of Public Health.

The people promoting the sitting scare may have been using other statistics, but it’s fair to say that there’s no scientific consensus that sitting is worse than smoking. The message wasn’t an invention of the media, Buman said, but came from researchers trying to raise awareness. Awareness is good, but overplaying a scare is only going to get people to tune out or distrust scientists.

Everybody sits, and everybody dies, and teasing out the exact cause-and-effect relationship between the two is not a simple matter. There’s a body of evidence showing benefits of exercise, and harms of being sedentary. And there’s reason to believe that for those of us with desk jobs, it’s beneficial to get up periodically – unless it’s to go out and smoke.