Warning: watching too much TV can be really, really bad for your heart

by Carolyn Thomas

Every hour you spend watching television each day increases your risk of dying from heart disease by almost a fifth, say scientists in Australia.

The findings were reported last month in Circulation, the Journal of the American Heart Association.

Prof. David Dunstan, the study’s lead researcher from the Baker IDI Heart and Diabetes Institute in Victoria, Australia, had this message for members of the public:

“In addition to doing regular exercise, avoid sitting for prolonged periods and keep in mind to ‘move more, more often’. Too much sitting is bad for health.”

Couch potatoes were warned that their lifestyle also increased the risk of death from other causes including cancer. 

People who spent hours watching television greatly increased the chances of dying early from heart attacks and strokes, the Australia researchers found. Compared with those watching less than two hours of TV, people who sat in front of the box for more than four hours a day were 80% more likely to die for reasons linked to heart and artery disease.

The researchers monitored 8,800 adults for six years to see what impact watching television had on their long-term health. They found that each hour a day spent in front of the television increased the risk of death from all causes by 11%. It also raised the risk of dying from cancer by 9% and the risk of heart disease-related death by 18%.

The Aussie scientists warned it was not only “telly addicts” whose lifestyles put them in danger. They claimed that any prolonged sedentary behaviour, such as sitting at an office desk or in front of a computer, may pose similar risks. It also made no difference whether or not a person was overweight or obese.

However, a University of Queensland systematic review of eight studies examining the link between occupational sitting and cardiovascular risks has since revealed conflicting evidence. Four of these studies found an increased risk of coronary heart disease with prolonged sitting at work, but three others showed no association and one found an increased cardiovascular risk with occupational activity. Among four studies of diabetes risk and occupational sitting, three studies found an increased risk with sitting, while an additional prospective study found no association. Six studies assessed mortality risk with occupational sitting, four of which found an increased risk, while one study found no association – and one showed a decreased mortality risk for those with sedentary occupations. Find out more about this review published in the American Journal of Preventive Medicine.

Meanwhile, Prof. Dunstan added:

“Even if someone has a healthy body weight, sitting for long periods of time may still have an unhealthy influence on their blood sugar and blood fats.”

Find out more about this study.

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