Source: Medical Research Council
New research from the Medical Research Council (MRC) has provided fresh insights into the lifestyle factors contributing to heart disease, which causes 193,000 deaths a year and is responsible for a third of the UK’s deaths.
For almost a decade, researchers from the MRC Epidemiology Unit followed 13,197 middle-aged, healthy men and women in the EPIC-Norfolk study and found that every hour a day spent in front of the television multiplied their risk of death from heart disease by a factor of 7%, even after accounting for other well-known risk factors like lack of exercise, smoking, obesity and poor diet.
Study participants with a history of related diseases such
| How much is a 7% increase? |
0 Hours of TV a Night (normal risk) = 10%
1 Hour of TV a Night = 10.7%
2 Hours of TV a Night = 11.45%
3 Hours of TV a Night = 12.25%
4 Hours of TV a Night (national average) = 13.1%
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as strokes and heart attacks were excluded from the study, and researchers measured television viewing time from questionnaires completed by participants.
Over the 10 year study, 373 of the 13,197 participants (1 in 35) died from heart disease. Taking account of all the variables, the amount of time spent watching television was a significant marker of their likelihood of death from heart disease. Scientists estimated that 8% of these deaths, 30 people, might have been avoided if TV viewing times had been reduced from the UK average of four hours a day to just one hour.
Dr Katrien Wijndaele co-author of the study from the MRC warned:
“Our bodies are not designed to sit for long periods and we should be aware that.... It might seem obvious that watching TV is linked to heart disease but it’s really crucial that we look closely at how our lifestyles affect our health in order to develop more effective ways of improving the health of the nation. This type of research is a crucial part of informing public health advice.
“We need further research to see if other sedentary activities, like sitting behind a computer or in the car, generate the same results. However, we chose to focus on TV as it’s the most widespread sedentary leisure activity where people have an active choice to dramatically change their behaviour.”
Dr Ulf Ekelund, co- author of the study from the Medical Research Council said:
“If someone’s normal risk of death by heart disease (taking into account other variables like lifestyle, gender and age) is 10%, then just one hour a day of watching TV increases this risk by a factor of seven percent to 10.7% - a small but significant rise. So if my normal risk of dying by heart disease was 10% and I also watched four hours of television a day (the national average) my risk would jump to 13%.
“Substituting watching TV and sitting down for exercise such as brisk walking is the ultimate goal, but watching a couple of hours less TV a night and being physically active for at least 30 minutes a day can substantially reduce our risk of heart disease.
“In the future, doctors could use the number of hours spent in front of the TV as part of their assessment of our overall risk of heart disease.”
The study forms part of the MRC’s ongoing commitment to tackling lifestyles affecting health and was carried out in collaboration with the EPIC-Norfolk study and the Institute of Public Health, University of Cambridge. It is published today in the International Journal of Epidemiology.
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