July 27, 2026, 6:02 pm | Read time: 4 minutes
Regular and prolonged TV watching changes certain brain structures. Interestingly, TV consumption affects women and men differently. FITBOOK explains the background of the current study and the potential fate awaiting binge-watchers.
Excessive and prolonged TV watching has never had a good reputation. A recent study from the University of Southern California now reveals the true extent of its harmfulness. Constant TV watching apparently promotes alarming changes in the brain. This is not solely due to sitting, as stated in the study published in the journal “Alzheimer’s and Dementia: Journal of the Alzheimer’s Association.”1 Men should pay particular attention, as their brains seem especially vulnerable to prolonged TV watching.
It Depends on What We Do While Sitting
Lack of movement increases the risk of numerous health problems, including cognitive decline and dementia. But is every form of sitting equally problematic? Does it make a difference whether we analyze complex problems at a desk or let ourselves be entertained by a screen? This is precisely the question Prof. David Raichlen and his team sought to investigate. “For years, we focused on how much time people spend sitting,” the scientist emphasizes in a university statement.2 Perhaps the ‘how’ is significantly more decisive. They suspected that simply looking at the total number of sitting hours might be too simplistic.
How the Study Was Conducted
The researchers analyzed data from 1,712 women and men with an average age of 53 years. All participants were part of the Atherosclerosis Risk in Communities (ARIC) long-term study, which examines the cardiovascular and brain health of U.S. citizens. As early as the late 1980s, participants were asked how often they watched TV in their leisure time and how much time they spent sitting during their workday. The scale ranged from “never/rarely” to “very often.” Between 2011 and 2013, about 22 years later, the brains of the surviving participants (now between 67 and 90 years old) were examined using MRI. Individuals with a previously diagnosed dementia were excluded from the analysis.
A Lot of TV, Less Brain Volume?
It was found that participants who reported watching a lot of TV had different brain structures compared to those who watched less. In particular, the brain regions associated with the early signs of Alzheimer’s disease had a smaller volume. They also showed changes in the white matter, which is linked to an increased risk of cognitive decline. This is likely due to vascular health: The scans suggest that passive sitting primarily affects the health of the fine blood vessels in the brain. This can endanger the nutrient supply to important areas like the thalamus–a central hub in the brain–in the long term. These differences persisted even when researchers considered factors such as physical activity, diabetes, body mass index, smoking, and alcohol consumption. Interestingly, sitting and working at a desk for several hours a day did not show the same correlations. On the contrary, the brains of these individuals had a more pronounced frontal lobe.
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Why Men Should Turn Off the TV More Often
Men seemed particularly susceptible to these changes. When the MRI scans were broken down by gender, researchers found that their brains were especially vulnerable to prolonged TV watching. They have no explanation for this. Possible reasons could be hormonal differences, getting up occasionally, engaging in side activities like knitting, or simply a different resilience to certain aging processes. The researchers also suspect that women in the study were less affected because they interrupted their sitting more often–for example, to quickly do something around the house. This ‘intermittent’ sitting seems to protect the brain better than hours of uninterrupted sitting.
Is Passive Sitting the Unhealthiest Form of Sitting?
Sitting without much mental engagement, like prolonged TV watching, is detrimental to (brain) health. Although much of the study is based on not always accurate self-reports, Prof. David Raichlen and his team suspect a link between binge-watching and an increased risk of dementia. However, the topic is too complex for simple conclusions. Therefore, it urgently needs to be researched whether TV itself directly damages the brain or if other factors play a role. Movement remains important in minimizing the risk of cognitive diseases. However, it seems to make a difference whether one lounges on the sofa, solves crossword puzzles, or is entertained by a reality soap.
What does this mean for us? It’s not just about sitting, but what we do while sitting. Those who puzzle or read at a desk keep their brains active. Those who only passively consume risk losing brain substance in the long term–and unfortunately, this is independent of whether one goes for a jog in the evening.