- A new study found that reducing time spent watching television to less than one hour per day could prevent 11% of cases of coronary heart disease
- Researchers found this was the case regardless of the genetic makeup of the individuals.
- The study did not find that computer use for leisure activities had an impact on the risk for coronary heart disease.
Sitting down to enjoy your favorite television show at night may be your evening ritual, but new research indicates too much TV time may have some serious health implications. A new study found watching more than an hour of TV daily was associated with an increased risk of coronary heart disease, regardless of genetic makeup.
The study, which was published in the journal BMC Medicine, set out to find the connection between time spent watching TV and using a computer for leisure, someone’s individual DNA, and their risk of coronary heart disease.
Scientists concluded, assuming a causal link, that 11% of cases of coronary heart disease could be prevented if people watched less than an hour of television per day.
Those who watched more than four hours of television per day were at the greatest risk of the disease, regardless of their genetic predisposition. Individuals who watched two to three hours of television per day had a 6% lower rate of developing the disease, and those who reported watching less than an hour of TV had a 16% lower rate. Scientists found this was specifically associated with television usage—using a computer for leisure did not impact disease risk.
Researchers used the UK Biobank, a study of over 500,000 adults who have been monitored for 12 years. Of these, data from 373,026 participants of European ancestry, ages 40 to 69, and without cardiovascular disease were used. Scientists scored the participants based on their genetic risk of developing coronary heart disease which is determined by 300 genetic variants, called a polygenic risk score. Those with higher scores were more likely to develop the disease. Participants then self-reported TV viewing and computer use with touch-screen questionnaires.
“Limiting the amount of time sat watching TV could be a useful, and relatively light touch lifestyle change that could help individuals with a high genetic predisposition to coronary heart disease in particular to manage their risk,” Youngwon Kim PhD, an author of the study.
Scientists aren’t so sure why television, in particular, may be related to an increased risk of heart disease, but they hypothesised in the release that because people tend to watch TV after dinner, which is often a very high-calorie meal, it may have a stronger impact than computer use. They added that this may lead to higher levels of glucose and lipids in the blood.
“We know that a sedentary lifestyle and not moving is shown to be a cardiovascular risk,” explains Dr Stacey Ellyn Rosen, a cardiologist and co-author of Heart Smarter for Women: Six Weeks to a Healthier Heart, who was not associated with the study. “When we lump sedentary lifestyle activities, like sitting and not moving, especially with our new working models, it would be simpler to assume anytime we’re sitting it has the same impact.”
But Dr Rosen explains that television watching is often associated with snacking (sometimes with alcohol or sugary drinks) or napping on and off (meaning you have poor sleep habits), both of which can have some serious heart health consequences. In comparison, computer use tends to include more actively using your brain and even standing or moving for periods of time.
What is coronary heart disease?
Symptoms of coronary heart disease differ from person to person, but many do not develop symptoms until they experience chest pain, a heart attack, or cardiac arrest, according to Health Direct.
The cause of coronary heart disease depends on the specific type diagnosed but is often associated with cholesterol and genetics.. The study suggests that one of the major risk factors for heart disease is sedentary behavior, like sitting in front of a television instead of being physically active.
Lifestyle changes like diet and exercise, medications, and regular visits to the doctor can help improve heart health and help you prevent heart disease. Dr Rosen says more than half your risk for coronary heart disease is preventable by the choices we make.
“The World Health Organization recommends reducing the amount of sedentary behavior and replacing it with physical activity of any intensity as a way of keeping healthier,” Katrien Wijndaele PhD, a study author. “While it isn’t possible to say for certain that sitting watching TV increases your risk of coronary heart disease, because of various potential confounding factors and measurement error, our work supports the WHO’s guidelines. It suggests a straightforward, measurable way of achieving this goal for the general population as well as individuals at high genetic risk of coronary heart disease.”
Dr Rosen encourages getting in little bits of movement every day, even if it’s just walking for a few minutes. She adds adding heart-healthy foods to your diet over time can benefit your heart health immensely as well.