Could binge-watching TV actually kill you?
That’s what some media headlines proclaimed after the publication last week of a new study from Japan.
Published in the American Heart Association’s journal Circulation, the study found that middle-aged to older adults who regularly watched more than five hours of TV daily were more than twice as likely to die of a pulmonary embolism (a blood clot in the arteries that carry blood to the lungs) than their peers who watched for 2½ hours or less.
Those results are certainly interesting — and potentially important. Here in the United States, an estimated 60,000 to 100,000 people die of pulmonary embolisms each year, and sitting for prolonged periods of time has been identified as a potential risk factor for such blood clots (which typically travel to the lungs from a vein in the legs).
But the study comes with several important caveats (which I’ll get to in a minute), so any media claims about binge TV viewing killing you are, well, a bit overdramatic.
For the study, a team of researchers from Japan’s Osaka University analyzed data collected from 86,024 Japanese adults who were participating in a larger ongoing health study. At the start of the current study (1988-1990), the participants were aged 40 to 79, and none had had a history of cancer, stroke, heart attacks or pulmonary embolism.
Among the information collected from the participants was the amount of time they said they spent watching TV each day.
The study followed the participants for an average of 19 years (until 2009). During that time, 59 of them died from pulmonary embolism, as recorded on their death certificates. Thirteen of those deaths occurred among people who said they watched TV for five or more hours daily, 27 among those who watched for 2½ to five hours daily, and 19 among those who watched for less than 2½ hours daily.
Using those numbers, the researchers calculated that death from pulmonary embolism was 70 percent higher among the people who watched TV from 2½ to five hours daily compared to those who watched TV for less than 2½ hours.
And the risk for people who watched five or more hours daily was 2.5 times higher.
Overall, the researchers found that the risk of dying from a pulmonary embolism increased 40 percent for each additional two hours of daily TV watching.
The findings take into account a long list of confounding factors, such as smoking status, body mass index and time spent walking or playing sports daily.
“Prolonged television watching is a substantial risk factor for mortality from pulmonary embolism,” Iso and his colleagues conclude.
Limitations and implications
But this research, as I’ve already noted, comes with several important caveats.
To begin with, the study was observational, which means it can’t determine cause and effect. Some other confounding factor, not identified in the study, might explain the results.
In addition, the participants were asked to provide the information themselves — and only once. Some of the participants may not have been accurate with their assessments of their TV-viewing habits, and those habits may have changed significantly during the 19 years of the study.
Furthermore, pulmonary embolisms are, relatively speaking, rather rare. So even if the increased risk observed in this study is valid, that risk remains rare.
Still, this study’s findings supports growing evidence from many sources on the health risks of sedentary behavior, including an increased risk of heart disease, diabetes, colon cancer, depression — and early death.
So even though this particular study about pulmonary embolisms and TV viewing may not be definitive, we do, in general, need to get up and move around more — yes, when we’re guiltily binging on “Stranger Things” or “Orange Is the New Black,” but also when we’re doing anything that has us sitting for long stretches of time.
That would include, um, even reading a book.
FMI: You can read the study in full on Circulation’s website.