A team from the epidemiology group of the British Medical Research Council (MRC), the University of Cambridge and the University of Hong Kong in China said that regardless of an individual's genetic composition, watching too much TV was found to be associated with an increased risk of coronary heart disease. In a study recently published in BMC medicine, scientists show that - assuming causality - if people watch TV for less than an hour a day, 11% of coronary heart disease cases can be prevented**
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Coronary heart disease is one of the leading causes of death in the UK, with about 64000 deaths a year, according to the British Heart Foundation. In Britain, one in eight men and one in 15 women die from the disease. In addition, people with coronary heart disease are twice as likely to have a stroke.
One of the main risk factors for coronary heart disease is sedentary behavior - in other words, sitting for a long time rather than physical exercise. To study the link between time spent on screen based sedentary behavior, such as watching TV and using computers in their spare time, individuals' DNA and their risk of coronary heart disease, the researchers examined data from the UK Biobank. It is understood that the study covered more than 500000 adults who were prospectively followed for about 12 years.
The team created a polygenic risk score for each person - based on 300 genetic variants known to affect their risk of coronary heart disease, and created their genetic risk of coronary heart disease. As expected, people with high polygenic risk scores are at greatest risk of the disease.
People who watch TV for more than four hours a day have the greatest risk of the disease, regardless of their polygenic risk score. Compared with these people, people who watch TV for two to three hours a day have a relatively low rate of 6%, while those who watch TV for less than one hour have a relatively low rate of 16%. These associations were not affected by genetic susceptibility and other known risk factors.
Leisure time using computers does not seem to affect disease risk.
The corresponding author of the study, an assistant professor at the University of Hong Kong Dr youngwon Kim, visiting researcher of MRC Epidemiology Group, said: "Our study provides unique insights into the potential role of limiting TV viewing in the prevention of coronary heart disease. People who watch TV for less than one hour a day are less likely to develop the disease, which has nothing to do with their genetic risk. Limiting TV viewing time may be a useful and relatively lightweight lifestyle change, especially to help people with a high genetic predisposition to coronary heart disease control their risk."
The last author of the study Dr Katrien Wijndaele of the MRC Epidemiology Group pointed out: "Coronary heart disease is one of the leading causes of premature death, so it is important to find ways to help people manage their risk by changing their lifestyle. The World Health Organization recommends reducing sedentary behavior and replacing it with any intensity of physical activity as a way to stay healthier. Although it is not certain that sitting and watching TV will increase your risk of coronary heart disease, there are various potential confounding factors and factors Measurement error, but our work supports the guidelines of the World Health Organization. It proposes a direct and measurable method to achieve the goal of the general population and individuals at high genetic risk of coronary heart disease. "
The team points out that there are several potential reasons to explain the link between television viewing and the risk of coronary heart disease - especially why no link was found to computer use. Watching TV often happens in the evening after dinner, which is usually our highest calorie meal. In addition, people often eat more snacks while watching TV than when surfing the Internet. Finally, watching TV is often a long time, and people who use computers are more likely to interrupt their activities.