Where it used to be the case that we were confined to the offerings of free-to-air TV, streaming platforms have steamrolled the TV landscape. Now, simply hitting enter on the keyboard presents us with all manner of viewing options and not surprisingly, the lure to the couch or bed has never been greater as we binge-watch a new series or the latest blockbusters. Couple this with anxiety around socialising as the world begins its awkward tip-toe towards normality, and it seems that more and more of us are foregoing the outdoors and interactions away from the screen in favour of TV viewing. But as a recent study has found, more than one in 10 cases of coronary heart disease could be prevented if we reduced TV viewing to less than an hour a day.
Coronary heart disease is a result of fatty material building up inside the coronary artery. This causes them to narrow, thereby reducing the heart’s blood supply. According to researchers, simply cutting down on time spent in front of the TV could help lower the risk of developing the disease.
The study, published in the journal of BMC Medicine, utilised data from 373,026 white British people aged 40-69 who were part of an endeavour known as the UK Biobank study. When recruited for the study, none of the participants had coronary heart disease or stroke. Only when researchers examined the national death registry and hospital admission records up to autumn of 2022 did they discover 9,185 cases of the disease in participants.
The study took into account factors associated with coronary heart disease like genetic history of the disease, body mass index, age, sex, smoking status, diet, amount of physical activity and level of deprivation, and yet still the greater amount of TV watched proved to be a greater risk of developing coronary heart disease. Compared with people who watched four or more hours of TV a day, those who watched an hour or less had a 16 per cent lower risk of developing coronary heart disease, while those who watched two to three hours a day had a six per cent lower risk. This trend held across all ages and all levels of genetic risk.
As Dr Youngwon Kim, an assistant professor at the University of Hong Kong and an author on the research, explained to The Guardian, “Reducing time spent watching TV should be recognised as a key behavioural target for prevention of coronary heart disease, irrespective of genetic susceptibility and traditional risk markers.”
As the team of researchers discovered, excessive TV viewing time is associated with adverse levels of cholesterol and glucose in the body, however they are yet to examine exactly what is behind the correlation. “Unfavourable levels of these cardiometabolic risk markers may then lead to increased risk of developing coronary heart disease,” said Kim.
It’s worth noting that no link was found between amount of leisure-time computer use and the risk of coronary heart disease, something researchers put down to greater reliability in recalling TV viewing and other factors like snacking while watching TV, or TV watching tending to be uninterrupted and greater in duration. Though researchers can’t prove that TV watching is driving the rise in coronary heart disease risk, they estimate about 11 per cent of coronary heart disease cases could be prevented if TV watching was cut down to less than an hour a day.
As Naveed Sattar, a professor of metabolic medicine at the University of Glasgow, explained: “There is abundant other evidence that increasing activity time by replacing time spent sitting helps lower body fat levels and prevents weight gain, improves blood pressure and blood fat levels, and lowers diabetes risks. All such improvements, in turn, are known to lessen heart attack and stroke risks.”