Five Ways That TV Can Harm Your Health

Couch potatoes beware: Watching the tube for two to three hours a day or more is linked to higher risk for type 2 diabetes, cardiovascular disease, and higher rates of early death from all causes, according to new research published today in the Journal of the American Medical Association (JAMA). The culprit is the couch potato lifestyle that frequently accompanies excessive viewing, the researchers report. With the average American logging five hours a day in front of the tube, sitting is replacing exercise.

TV viewing is associated with unhealthy eating, setting the stage for weight gain, the study indicates. Packing on pounds, in turn, boosts risk for diabetes, heart attacks, and a shorter life. Studies also link excessive tube time to sleep deprivation (another heart health hazard) and even nearsightedness in kids. Don’t blame the TV - it can’t shove you onto the couch or serve up a fast food meal. If your main form of physical activity is pushing buttons on the remote, take a look at how these habits can impact your health:

1. Type 2 Diabetes. About 26 million Americans have diabetes, which quadruples risk for heart attack and stroke. The main risk factors for type 2 diabetes include being overweight, a sedentary lifestyle, poor diet (too many fried foods, too much processed meat and sugar-laden beverages), and family history. The JAMA study, which pooled results from earlier studies of 175,938 people, found that two hours of TV viewing daily ups risk by 20 percent.

Best prevention strategies: If you’re heavy, dropping even a few pounds can make a dramatic difference. In a study of people who already had pre-diabetes, those who shed 5 to 7 percent of their body weight (10 to 14 pounds for a 200-pound person) and exercised 150 minutes per week trimmed risk of progressing to full-blown diabetes by 58 percent. Exercise and weight loss also improve insulin resistance, the problem that leads to diabetes.

2. Cardiovascular Disease (CVD). This includes heart attacks, high blood pressure, angina (chest pain due to reduced blood supply to the heart), stroke and heart failure. The JAMA study found a 15 percent increased risk for fatal or nonfatal CVD among those who watched TV two hours a day. A recent Australian study found that the more screen exposure kids get, the higher the risk that arteries in their eyes will narrow, which could mean CVD later in life.

Best prevention strategies: Avoid smoking, exercise at least 30 minutes for five or more days a week, have your cholesterol and blood pressure checked, and if they’re high, get them under control via diet, exercise and, if necessary, medication. Maintain a healthy weight and reduce stress (exercise helps with both).

3. All-Cause Mortality. The JAMA study found that watching two hours of TV daily boosted risk of death from all causes during the study period by 13 percent. Worse: the risks appeared to rise with TV viewing of more than three hours daily, due to the couch potato lifestyle linked to excessive screen time.

4. Sleep Deprivation. We need between seven and eight hours of sleep daily but most adults don’t get that much. According to a National Sleep Foundation study watching the tube in bed or near bedtime is partly to blame. Skimping on slumber lifts risk for obesity, heart attacks, and car accidents. Multiple studies show that light at night, including light from the TV, boosts women’s risk of breast cancer.

Best prevention strategies: Turn off the TV at least one hour before bedtime, since the bright light from the screen stimulates the brain, making it harder to doze off. Develop good sleep hygiene.

5. Nearsightedness in Kids. Myopia (nearsightedness) affects 1.6 billion people globally. By 2020, the number is expected to hit 2.5 billion. Rates are highest in countries where kids watch the most TV and play computer games instead of playing outdoors. In Tokyo and Hong Kong, 30 to 50 percent of kids are myopic, versus 20 percent in the US. Myopic kids spend an average of 4.3 fewer hours per week outside than kids with normal vision and logged about four more hours of TV time weekly, a 2009 study found.

Best prevention strategies: Spending two hours a day outdoors reduces kids’ risk of nearsightedness by encouraging them to focus on objects in the distance, which helps strengthen their eyesight. Outdoor play also helps kids maintain a healthy weight.