<Cancers and cardiovascular disease were associated with viewing TV New research, led by the University of Glasgow>
August 2, 2020 • jainendra joshi • MEDICAL AND HEALTH



If adults spent no quite two hours watching TV every day , they might minimise their exposure to the

health risks related to TV.

New research, led by the University of Glasgow and published today in Mayo Clinic Proceedings, studied

UK Biobank data and found that the majority of health risks associated with too much TV time could be

reduced if people limited their viewing time to two hours a day, or less.

A person holding the remote in front of the TV

The researchers found that the lowest overall health risks from diseases including cancers and

cardiovascular disease were associated with viewing TV for 2 hours or less per day. Further analysis

estimated that 6% of all-deaths and 8% of cardiovascular deaths were attributable to TV time. They also

showed that potentially, if all participants limited TV time to 2 hours a day, 5.62% of all deaths and 7.97%

of deaths due to cardiovascular disease could have been prevented or delayed.

The researchers also looked at the potential benefits of substituting TV time with healthier activities such

as walking. They found that those people who would benefit most from replacing longer periods of TV

time with more time spent doing healthier activities, are those who currently only spend very small

amounts of their day doing those healthier activities.

Current physical activity guidelines in UK encourage 150 minutes of moderate physical activity or 75

minutes of vigorous activity every week . On the other hand, current sedentary guidelines lack specific

advice, and only suggest that people limit the time they spend sitting. There is currently no

recommendations as to what might be a low risk amount of time to spend sitting watching TV each day.

In order to understand the risks, researchers examined lifestyle and demographic data from 490,966 UK

Biobank participants aged 37-73 years who were recruited between 2006-2010. Participants were

followed up until 2016-2018 and their data was linked to national routine death and disease registries. 

In order to reduce the chance of the results being due to reverse causality (where poor health leads to

increased TV time) participants with non-communicable disease, cardiovascular disease and cancer

were excluded. Similarly, the researchers excluded all those with an adverse health event within two

years of recruitment.

Dr Hamish Foster from the University of Glasgow’s Institute of Health and Wellbeing, who led the

study, said: “This study adds more weight to the evidence that more time spent watching TV is

likely to be detrimental to health.

“Our study suggests limiting TV time could delay or prevent tons of adverse health. However, there's

still more work to be done before we will make firm TV time recommendations. TV time is just one of a

number of potentially sedentary behaviours, which also includes screen time watching videos on your

phone, which may all contribute to adverse health outcomes. Also, there are many other contributory

factors, such as unhealthy snacking and lower socioeconomic status, that are also strongly associated

with both TV time and poor health outcomes. Further research is required to know of these factors and

inform future advice and guidelines.”

The study ‘Understanding what proportion TV is just too much: A non-linear analysis of the

association between television viewing time and adverse health outcomes’ is published in

Mayo Clinic Proceedings.