Sitting Too Much And Your Brain
We know that too much time spent sitting daily can raise the risk of heart disease, diabetes and premature death. And now a new study from the University of California, Los Angeles, suggests that sitting too much can be bad for the brain. Specifically, the research links time spent sitting to the thinning of the medial temporal lobe (MTL), an area of the brain that is key to learning and memory. A team of UCLA researchers reached this conclusion after studying the lifestyle habits of 35 cognitively healthy people ages 45 to 75, who spent anywhere from three to 15 hours sitting daily. All 35 underwent brain scans with a high-resolution MRI. Results showed that sedentary behavior “is a significant predictor of thinning of the MTL” and that the effects aren’t offset by even high levels of physical activity. What’s more, the researchers found that every added hour of sitting daily leads to a two percent decrease in MTL thickness. They noted that MTL thinning could be a precursor to cognitive decline and dementia in middle-aged and older adults.
My take? In recent years, we’ve heard a lot about the negative health effects of sitting for prolonged periods of time. The UCLA study didn’t prove that a certain number of hours spent sitting daily caused the MTL thinning observed, although it did show an association between the two. The one bright spot in all the research about the negative effects of sitting came from a British study published in 2015 showing no link between sitting and an increased risk of early death among more than 5,000 men and women tracked for 16 years. This was the longest follow-up among all of the studies that looked at the health effects of time spent sitting. However, the British team did conclude that “the absence of movement rather than the time spent sitting itself” is detrimental to health.
Prabha Siddarth et al, “Sedentary behavior associated with reduced medial temporal lobe thickness in middle-aged and older adults.” PLOS One, April 12, 2018, doi.org/10.1371/journal.pone.0195549
Also in this week’s bulletin: