Too Much Television Increases Risk for Heart Disease
Another reason to turn off the television and go for a walk instead: People who watch more television in their early adulthood were more apt to develop heart disease risk factors as they moved into middle age.
Researchers from the University College London studied the television and exercise habits of 5,629 men and women born in Britain in 1958. Baseline measurements of weekly frequencies of television watching and exercise participation were taken in 1981, when the participants were 23 years old. The subjects were then reassessed at the age of 44, with 15 biological cardiometabolic risk factors also measured.
The study found that television watching was strongly associated with elevated triglycerides, low HDL cholesterol, a higher BMI and waist circumference, and elevated blood pressure – all factors that make up the metabolic syndrome which increases the risk for coronary artery disease, stroke, and type 2 diabetes.
Increased calories may likely contribute to the increased risk, but the study did not evaluate that aspect. Many people snack on high calorie, high fat, and high sodium snacks while watching television. Also, studies have indicated that people who eat in front of the television are not mindful of their intake and consume more calories overall.
Although about one-fifth of the participants were physically active, participating in at least 150 minutes of moderate to vigorous physical activity per week, their risk factors remained elevated when combined with television watching.
"When we took into account physical activity, the negative effects of TV viewing persisted," confirmed Emmanuel Stamatakis, lead author of the paper and a senior research associate at University College London. "A likely explanation is that the harmful effects of prolonged sitting cannot be simply compensated by doing some physical activity. In other words, the mechanisms of action of the harms of sitting are not the opposite of the benefits of exercise."
He concludes by saying that sitting in front of the television for long periods of time should be avoided. In both the UK and the US, adults watch an average of three to four hours of television each day. “This is simply too much,” says Stamatakis. “given that most of us have sedentary jobs, drive or commute by motorized transport, and have lots of other opportunities to sit.”
Source: American Heart Association’s Joint Conference: Nutrition, Physical Activity, and Metabolism (San Francisco)