A recent study revealed that spending a lot of time watching television during middle age may be linked to changes in brain structure, including a decrease in the size of some areas associated with memory and cognitive functions.
The study, published in the journal "Alzheimer's and Dementia," showed that people who reported frequently watching television in middle age showed, years later, signs associated with a decrease in the volume of important brain regions, as well as changes in the brain's white matter, which is tissue that plays a key role in transmitting signals between different brain regions.
David Reichlin, a professor of biological sciences and anthropology at the Dornsife College of Arts and Sciences at the University of Southern California and one of the senior researchers involved in the study, said that previous research has often focused on the duration of sitting, but the new findings suggest that it is also important to pay attention to the nature of the activity a person is doing while sitting.
The study was based on an analysis of data from approximately 1,700 people, with an average age of 53, who participated in the "Atherosclerosis Risk in Communities" (ARIC) study, which began in the United States between 1987 and 1989, with the aim of monitoring factors affecting heart and brain health.
The researchers asked participants to report how much television they watched during their leisure time, as well as to estimate the amount of time they spent sitting during work hours. More than 20 years later, the participants underwent MRI scans to detect changes in their brains.
The results showed that people who watched television frequently had differences in several brain regions compared to those who rarely watched it. These differences included reduced volume in areas associated with memory, decreased volume in the frontal and occipital lobes responsible for several executive functions and visual processing, and increased markers associated with changes in the brain's white matter.
The researchers explained that this relationship remained even after taking into account other factors that may affect brain health, such as physical activity, diabetes, body mass index, smoking, and alcohol consumption.
However, the study indicated that sitting itself may not be the primary problem, as other activities requiring sitting did not exhibit the same effects. Researchers found that people who spent extended periods working while seated did not show the same brain changes, perhaps because some office work requires sustained focus and mental engagement.
The researchers also noted that these correlations were more pronounced in men when analyzing MRI results according to gender.
The researchers noted some limitations in the study, including its reliance on participants' answers about the duration of television viewing, and the lack of MRI images at the start of the study, which makes it difficult to accurately determine when changes occurred.
Although more research is needed to understand the relationship between television viewing and brain health, scientists believe that future health advice may focus not only on reducing sitting time, but also on choosing more mentally stimulating activities during breaks, and reducing the time people spend passively watching television.
