Sitting around is bad for the brain, not just the heart, study finds

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While not everyone agrees that standing desks are the answer to all health problems, there’s mounting evidence that too much sitting around is not a good idea. The latest evidence is a UCLA study that found too much sitting is linked to changes in a section of the brain that is critical for memory.

Earlier studies have found that, just like smoking, too much sitting increases the risk of heart disease, diabetes and premature death. That made researchers at UCLA curious. They studied middle-aged and older adults to see how sedentary behavior influences brain health, especially regions of the brain that are critical to memory formation.

They found that sedentary behavior is a significant predictor of thinning of the MTL– the medial temporal lobe, a brain region involved in the formation of new memories — and that physical activity, even at high levels, is insufficient to offset the harmful effects of sitting for extended periods.

This study does not prove that too much sitting causes thinner brain structures, but instead that more hours spent sitting are associated with thinner regions, researchers said. In addition, the researchers focused on the hours spent sitting, but did not ask participants if they took breaks during this time.

A Swedish study last year found that the daily amount of physical activity was more important than the amount of time spend sitting to one’s overall health. That study did not look specifically at brain health, however.

However, they noted that MTL thinning can be a precursor to cognitive decline and dementia in middle-aged and older adults. Reducing sedentary behavior may be a possible target for interventions designed to improve brain health in people at risk for Alzheimer’s disease, the researchers said in a news release.

Study details

UCLA researchers recruited 35 people ages 45 to 75 and asked about their physical activity levels and the average number of hours per day they spent sitting over the previous week. Each person had a high-resolution MRI scan, which provides a detailed look at the medial temporal lobe, or MTL, a brain region involved in the formation of new memories.

The researchers next hope to follow a group of people for a longer duration to determine if sitting causes the thinning and what role gender, race, and weight might play in brain health related to sitting.

The study appears in the April 12 issue of PLOS ONE.


About the Author

Truman Lewis
Truman has been a bureau chief and correspondent in D.C., Los Angeles, Phoenix and elsewhere, reporting for radio, television, print and news services, for more than 30 years. Most recently, he has reported extensively on health and consumer issues for and