Coronary heart disease occurs when the accumulation of fatty substances in the coronary artery narrows the coronary artery and reduces the blood supply to the heart. Researchers say reducing the time spent in front of TV can reduce the risk of the disease. Reducing TV viewing time should be considered a key behavioral goal for the prevention of coronary heart disease, regardless of genetic susceptibility and traditional risk markers.
Although the team did not study the reasons behind this association, previous studies by researchers have found that excessive television viewing is associated with poor levels of cholesterol and glucose in the body. Adverse levels of these cardiac metabolic risk markers may lead to an increased risk of coronary heart disease.
Writing in the journal BMC medicine, the researchers reported how they used data from 373026 white Britons aged 40-69 who were part of a study known as the UK Biobank. In the team's study, none of the participants had coronary heart disease or stroke when recruited to the UK Biobank. However, by the fall of 2021, the researchers found 9185 cases of the disease among participants through the National Death Registry and hospital admission records.
The study showed that after taking into account the genetic risk of coronary heart disease calculated for each participant, as well as factors including body mass index, age, gender, smoking status, diet, physical activity and poverty, the more TV viewing, the greater the risk of coronary heart disease. Those who watched TV for an hour or less had a 16% lower risk of coronary heart disease than those who watched TV for four or more hours a day, while those who watched TV for two to three hours a day had a 6% lower risk.
The trend remained unchanged at all ages and levels of genetic risk, but those with a higher genetic risk of coronary heart disease were at greater risk, the researchers said. However, no link was found between the amount of computer use in leisure time and the risk of coronary heart disease, which may be due to factors such as eating snacks while watching TV, or watching TV longer and continuously.