New research reveals that long hours of viewing television along with low physical activity in early and mid-adulthood may raise the risk of poorer cognitive function later in life.
Physical activity guidelines generally recommend that adults aged 18-64 should engage in at least 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous-intensity aerobic activity each week. However, according to the Centers for Disease Control and Prevention (CDC) in the United States, only around 1 in 5 adults meet these recommendations.
It is well established that lack of physical activity and sedentary behavior can have negative implications for health, such as overweight and obesity, greater risk of type-2 diabetes and increased risk of cardiovascular disease. Increasingly, research is now suggesting that such behavior may also adversely affect brain function.
The latest research study, which included more than 3,200 adults, aged between 18-30, recorded participants' television viewing time and physical activity levels over a period of 25 years. In the study, high television viewing was defined as more than 4 hours daily, while low physical activity was defined as activity below 300 Kcal per 50-minute session, three times weekly. At the end of the 25-year study period, participants took part in tests that assessed their cognitive function, including memory, executive function and processing speed.
Of the participants, 17 percent had a long-term pattern of low physical activity over the 25 years, 11 percent had a long-term pattern of high television viewing and 3 percent had a long-term pattern of both.
The researchers found that high television viewing and low physical activity among participants were independently associated with significantly poorer cognitive function in mid-life, while subjects with both factors were nearly two times more likely to have worse cognitive function in mid-life. The findings demonstrate that even early and mid-adulthood may be critical periods for promotion of physical activity for healthy cognitive aging.
Sedentary behaviors, like TV viewing, could be especially relevant for future generations of adults due to the growing use of screen-based technologies. Increasing physical activity and reducing sedentary behavior beginning in early adulthood may have a significant public health impact.