Everybody knows being sedentary is bad for your heart. But a new study suggests watching lots of TV might be particularly bad for African Americans – and it was linked to more of a risk than having a job that requires sitting all day.
The study published Wednesday in the Journal of the American Heart Association said African Americans who watched more than four hours of television every day faced a 50% greater risk of heart disease and premature death compared to those who watched less than two hours.
But researchers also said the link between television watching and heart disease was not found in people who were physically active at least 150 minutes a week, which suggests exercise could offset the risks from binge-watching.
"TV watching occurs at the end of the day where individuals may consume their biggest meal, and people may be completely sedentary with hours of uninterrupted sitting until they go to bed," lead study author Jeanette Garcia said in a news release.
TV viewing is the most prevalent sedentary behavior in the United States, the study said. Given that African Americans report watching from 20% to 30% more TV than white Americans, researchers suggested getting people to cut back could be a potential target for improving the health in that high-risk group.
"Eating a large meal and then sitting hours at a time could be a very harmful combination," said Garcia, a professor of kinesiology and physical therapy at the University of Central Florida in Orlando.
"Snacking may also be an issue and, unfortunately, individuals typically are not snacking on fresh fruits and vegetables, but rather potato chips or other sweet or salty, high-calorie foods," she said. "At a desk job, workers are often getting up, going to a copy machine, talking with a colleague, going to a meeting or to the break room. It's not hours of uninterrupted sitting."
The study, in fact, saw no correlation between sitting at work and a risk of heart disease, matching findings from other researchers.
Too much TV time is probably harmful for any racial or ethnic group, researchers said, and they plan to further study why it might be a more harmful sedentary behavior.
Meanwhile, Garcia said doctors might want to ask their patients about their TV watching habits. Those who like to watch TV can take preventive measures, such as taking a brisk walk or jog, to offset the health risks.
Growing evidence has linked sedentary behavior to several risk factors for heart disease and stroke, including high blood pressure, obesity and Type 2 diabetes. African Americans experience disproportionately high rates of heart disease and stroke and a greater risk for cardiovascular disease at all ages, as well as a lower life expectancy by about five years compared with whites.
For the study, researchers reviewed data on 3,592 adults enrolled in the Jackson Heart Study, an ongoing community-based study following African Americans living in Jackson, Mississippi. Television habits, hours spent sitting at a desk and exercise were self-reported. During a follow-up period of more than eight years, there were 129 cardiovascular disease events, such as heart attacks, and 205 deaths.
Study participants who reported spending more time sitting at work were more likely to be female; younger; have a higher body mass index; higher family income; eat a healthier diet; and engage in more moderate physical activity. They were less likely to smoke or drink a lot of alcohol.
Those who watched several hours of television, on the other hand, were more likely to report lower incomes and education status; less physical activity; a higher BMI; being a current smoker; unhealthy eating; drinking heavier amounts of alcohol; and having high blood pressure.
Nearly one-third reported watching less than two hours of television daily; another 36% reported watching two to four hours; and 31% said they watched more than four hours of television.
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