Can too much TV be bad for you?

 

Can too much TV be bad for you? 

According to three new research, viewing a lot of TV in your midlife years may be hazardous for your brain health your senior years. It is also cool to find that young children are more likely to watch television and use cell phones and computers frequently, which can adversely affect their mental development.

People who reported watching moderate to large quantities of TV in their 40s, 50s, and early 60s had higher cognitive impairments and smaller gray matter volumes in their brains in their 70s and 80s, according to the studies, compared to those who reported watching very little TV in midlife. According to the researchers, gray matter is involved in a variety of brain activities, including muscle control, vision, hearing, and decision-making. Higher gray matter volumes have been linked to improved cognitive abilities. 

The research employed TV viewing as a surrogate for sedentary behavior, or time spent sitting, and will be presented this week at the American Heart Association's Epidemiology, Prevention - Lifestyle & Cardio metabolic Health Conference 2021. Sedentary behavior has been related to a number of health issues, including an increased risk of heart disease, cancer, type 2 diabetes, and premature death. Furthermore, frequent exercise isn't always adequate to compensate for time spent sitting, as evidenced by both the current and previous studies.

"After controlling for physical activity, we found that television viewing was still associated with cognitive function and gray matter volume, suggesting that this sedentary behavior may pose a unique risk to brain and cognitive health," said Ryan Dougherty, lead author of one of the studies and a postdoctoral fellow in the Department of Epidemiology at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland. Given that the biological processes that underpin dementia, such as brain degradation, tend to begin around middle age, Dougherty believes that "that's a moment [when] modifiable habits, such as excessive television consumption, can be targeted and reduced to promote healthy brain aging."

According to the researchers, several studies suggest that, among sedentary behaviours, TV watching poses particular hazards because it is a passive activity that does not require much cognitive stimulation.

"Not all sedentary behaviours are equal in the context of cognitive and brain health; non-stimulating sedentary activities like television viewing are linked to a higher risk of developing cognitive impairment, whereas cognitively stimulating sedentary activities [like reading, computer, and board games] are associated with maintained cognition and a lower risk of dementia," Dougherty said.

Two of the new investigations drew on data from the Atherosclerosis Risk In Communities Neurocognitive Study (ARIC-NCS), which began in the mid-1980s and enrolled people aged 45 to 64. They were asked how much TV they watched in their spare time at the time, and their responses were recorded as "never or rarely" (low TV watching), "occasionally" (medium/moderate TV watching), or "frequently/very often" (high TV watching) (high TV watching). In the 1990s, researchers followed up with the participants, asking those questions about their TV viewing habits and administering cognitive tests. Between 2011 and 2013, they underwent another evaluation that included brain MRI scans to test for structural markers of brain health, such as gray matter volume.

The ARIC-NCS study included 10,700 people, according to one study led by Priya Palta, an assistant professor of medical sciences and epidemiology at Columbia University. The findings of the participants' cognitive assessments, which included memory, language, and brain processing speed tests, were the focus of the researchers.

They discovered that persons who reported moderate to high TV consumption in midlife had a 7% higher decrease in cognitive function (based on test results) over a 15-year period than those who reported low TV viewing.

Another study, conducted by Kelley Pettee Gabriel, an epidemiology professor at the University of Alabama in Birmingham's School of Public Health, looked at data from roughly 1,600 ARIC-NCS participants, focusing on the outcomes of their MRI scans.

They discovered that people who reported moderate to high TV viewing had lower volumes of gray matter more than a decade later, indicating greater brain deterioration, compared to those who reported low TV viewing.

"Our findings suggest that the amount of television viewing, a type of sedentary behaviour," Palta said, "may be related to cognitive decline and imaging markers of brain health." "As a result, reducing sedentary behaviours like television viewing may be an important lifestyle modification target to support optimal brain health."

A third study, led by Dougherty, used data from the Coronary Artery Risk Development in Young Adults Study, which began in the mid-1980s but included people in their 30s at the start of the study and followed them for 20 years. The researchers analysed data from 600 participants who were asked how much time they spent watching TV each day and also had brain MRI scans.

They discovered that increased TV viewing was associated with lower gray-matter volume 20 years later. The researchers calculated that every one-hour increase in a person's daily average TV viewing time was associated with a 0.5 percent decrease in gray-matter volume. That's comparable to the amount of gray-matter atrophy seen over the course of a year in mid to late adulthood, according to Dougherty. Markers.

Future studies 

Although the studies discovered a link between TV viewing and cognitive decline and reduced brain volumes later in life, they cannot prove that excessive TV viewing caused these outcomes. Although the studies took into account some factors that may affect brain health, such as age, education level, and the presence of certain genes linked to Alzheimer's risk, they did not ask about total sedentary time or distinguish TV viewing from other forms of sedentary behaviours. The studies also relied on participants' reports of their TV viewing time, which could be inaccurate.

Furthermore, the studies do not explain why TV viewing was linked to these outcomes. It's unclear whether the link is due to sedentary behaviour or whether other factors associated with TV viewing, such as increased food consumption, may play a role.

More research is needed to confirm the findings, according to the researchers, including studies that use objective measures of sedentary behaviour (such as activity trackers) and those that look at differences in passive and active sedentary behaviour in relation to cognitive decline and brain health markers.