People who spend at least four hours a day watching TV may be at increased risk of developing blood clots, according to a new study in the European Journal of Preventative Cardiology.
Compared to those who watch less than 2.5 hours of TV per day, binge-watchers were found to have a 35 percent higher chance of developing these potentially fatal complications, regardless of how physically active they may be when not watching the box.
The researchers arrived at this conclusion after pooling data from three major studies examining the association between television viewing habits and venous thromboembolism (VTE), which includes blood clots in both the lungs and deep veins. Conducted in the US and Japan, these studies involved a total of 131,421 participants with an average age of 54 to 65 years and no prior history of VTE.
Participants were placed into one of two categories depending on how much time they spent watching TV, with those who binge watched more than four hours a day classed as “prolonged” viewers while those who watched less than 2.5 hours per day labeled “seldom/never” viewers. The average duration of follow-up for the three studies ranged from five to 20 years, during which time 964 cases of VTE were reported.
Overall, prolonged TV viewers were 1.35 times more likely to develop VTE than seldom/never viewers, with this outcome seemingly independent of age, sex and body mass index.
While these findings are observational and don’t provide any evidence that watching TV actually causes blood clots, study author Dr Setor Kunutsor explained in a statement that “prolonged TV viewing involves immobilization which is a risk factor for VTE.”
“In addition, when you sit in a cramped position for long periods, blood pools in your extremities rather than circulating and this can cause blood clots,” he said, adding that “if you are going to binge on TV you need to take breaks.”
Previous research has indicated that physical activity eliminates the increased risk of developing blood clots associated with “sitting time,” although the results of this study suggest that the elevated risk of VTE associated with TV watching is not mitigated by exercise. The authors propose that this finding may reflect the fact that people tend to remain immobile for extended periods when watching television, “as opposed to sitting time which is characterized by breaks.”
They also mention that unhealthy snacks tend to go hand-in-hand with binge-watching and speculate that this may be a major contributing factor to the excess risk associated with watching TV.
“Our results suggest that we should limit the time we spend in front of the television,” said Kunutsor. “Long periods of TV watching should be interspersed with movement to keep the circulation going. Generally speaking, if you sit a lot in your daily life – for example your work involves sitting for hours at a computer – be sure to get up and move around from time to time.”