Sit Much less, Suppose Extra: Over 10hr Sedentary Time A Day Hike Dementia Danger


Abstract: Adults over 60, who have interaction in additional than 10 hours of sedentary conduct day by day, have a heightened threat of dementia. The examine revealed that the sample of sedentary conduct all through the day mattered lower than the entire hours spent. Utilizing goal accelerometer information from over 50,000 individuals of the U.Okay. Biobank, the findings after six years pinpointed 414 dementia instances. Importantly, sitting occasions under 10 hours day by day didn’t point out elevated threat.

Key Details:

  1. The common American is sedentary for about 9.5 hours a day, near the 10-hour threshold discovered within the examine.
  2. The examine employed wrist-worn accelerometers, worn 24/7 for per week, to objectively measure and classify behaviors of round 50,000 adults over 60.
  3. After adjusting for numerous demographics and life-style traits, dementia threat started to surge after 10 hours of day by day sedentary time.

Supply: USC

Adults aged 60 and older who spend extra time participating in sedentary behaviors like sitting whereas watching TV or driving could also be at elevated threat of growing dementia, in line with a brand new examine by USC and College of Arizona researchers.

Their examine confirmed the chance of dementia considerably will increase amongst adults who spend over 10 hours a day participating in sedentary behaviors like sitting — a notable discovering contemplating the common American is sedentary for about 9.5 hours every day.

This shows an older man watching TV.
The examine builds on their earlier analysis, which used self-reported well being information to research how sure kinds of sedentary conduct, like sitting and watching TV, have an effect on dementia threat greater than others. Credit score: Neuroscience Information

The examine, printed on Tuesday, September 12 in JAMA, additionally revealed the way in which sedentary conduct is accrued over the course of the day didn’t matter as a lot as the entire time spent sedentary every day.

Whether or not spent in prolonged intervals spanning a number of hours or unfold out intermittently all through the day, complete sedentary conduct had an identical affiliation with dementia in line with examine creator David Raichlen.

“Many people are acquainted with the frequent recommendation to interrupt up lengthy intervals of sitting by getting up each half-hour or so to face or stroll round. We needed to see if these kinds of patterns are related to dementia threat.

“We discovered that when you keep in mind the entire time spent sedentary, the size of particular person sedentary intervals didn’t actually matter,” stated Raichlen, professor of organic sciences and anthropology on the USC Dornsife School of Letters, Arts and Sciences.

Researchers used information from the U.Okay. Biobank, a large-scale biomedical database of individuals throughout the UK, to research doable hyperlinks between sedentary conduct and dementia threat.

As a part of a U.Okay. Biobank sub-study, over 100,000 adults agreed to put on accelerometers, wrist-worn units for measuring motion, for twenty-four hours per day for one week. The researchers centered on a pattern of roughly 50,000 adults from this sub-study over the age of 60 who didn’t have a prognosis of dementia in the beginning of the examine.

The researchers then utilized a machine-learning algorithm to investigate the massive dataset of accelerometer readings and classify behaviors primarily based on completely different intensities of bodily exercise.

The algorithm was in a position to discern between several types of exercise equivalent to sedentary conduct versus sleeping. The accelerometer information, mixed with superior computing methods, supplied researchers with an goal measure of the time spent participating in several types of sedentary behaviors.

After a median of six years of follow-up, the researchers used inpatient hospital information and dying registry information to find out dementia prognosis. They discovered 414 instances optimistic for dementia.

Then, the staff adjusted their statistical evaluation for sure demographics (e.g., age, intercourse, training degree, race/ethnicity, continual circumstances, genetics) and life-style traits (bodily exercise, eating regimen, smoking and alcohol use, self-reported psychological well being) that might have an effect on mind well being.

Whole time spent sedentary every day drives dementia threat

Whereas excessive quantities of sedentary conduct have been linked with elevated threat of dementia, the researchers discovered that there have been sure quantities of sedentary conduct that weren’t related to dementia.

“We have been stunned to search out that the chance of dementia begins to quickly improve after 10 hours spent sedentary every day, no matter how the sedentary time was accrued.

“This means that it’s the complete time spent sedentary that drove the connection between sedentary conduct and dementia threat, however importantly decrease ranges of sedentary conduct, as much as round 10 hours, weren’t related to elevated threat,” stated examine creator Gene Alexander, professor of psychology and psychiatry on the Evelyn F. McKnight Mind Institute on the College of Arizona and Arizona Alzheimer’s Illness Analysis Middle.

“This could present some reassurance to these of us with workplace jobs that contain extended intervals of sitting, as lengthy we restrict our complete day by day time spent sedentary,” stated Raichlen.

The examine builds on their earlier analysis, which used self-reported well being information to research how sure kinds of sedentary conduct, like sitting and watching TV, have an effect on dementia threat greater than others.

“Our newest examine is a part of our bigger effort to grasp how sedentary conduct impacts mind well being from a number of views. On this case, wearable accelerometers present an goal view of how a lot time folks dedicate to sedentary conduct that enhances our previous analyses,” stated Raichlen.

Extra analysis is required to ascertain causality and whether or not bodily exercise can mitigate the chance of growing dementia, the authors stated.

Concerning the examine

Along with Raichlen and Alexander, different authors of the examine embrace Daniel H. Aslan, M. Katherine Sayre, Mark H.C. Lai and Rand R. Wilcox of USC; Pradyumna Okay. Bharadwaj, Madeline Ally and Yann C. Klimentidis of the College of Arizona; and Silvio Maltagliati of the Université of Grenoble Alpes, France.

Funding: The examine was supported by grants P30AG072980, P30AG019610, R56AG067200, R01AG064587 and R01AG072445 from the Nationwide Institutes of Well being and funding from the state of Arizona, the Arizona Division of Well being Companies and the McKnight Mind Analysis Basis. The content material is solely the accountability of the authors and doesn’t essentially signify the official views of the Nationwide Institutes of Well being.

About this dementia analysis information

Creator: Nina Raffio
Supply: USC
Contact: Nina Raffio – USC
Picture: The picture is credited to Neuroscience Information

Unique Analysis: Closed entry.
Sedentary Habits and Incident Dementia Amongst Older Adults” by David Raichlen et al. JAMA


Sedentary Habits and Incident Dementia Amongst Older Adults


Sedentary conduct is related to cardiometabolic illness and mortality, however its affiliation with dementia is unclear.


 To research whether or not accelerometer-assessed sedentary conduct is related to incident dementia.

Design, Setting, and Contributors 

 A retrospective examine of prospectively collected information from the UK Biobank together with 49 841 adults aged 60 years or older and not using a prognosis of dementia on the time of carrying the wrist accelerometer and residing in England, Scotland, or Wales. Observe-up started on the time of carrying the accelerometer (February 2013 to December 2015) and continued till September 2021 in England, July 2021 in Scotland, and February 2018 in Wales.


Imply day by day sedentary conduct time (included within the major evaluation) and imply day by day sedentary bout size, most day by day sedentary bout size, and imply variety of day by day sedentary bouts (included within the secondary analyses) have been derived from a machine studying–primarily based evaluation of 1 week of wrist-worn accelerometer information.

Essential Final result and Measures  

Incident all-cause dementia prognosis from inpatient hospital information and dying registry information. Cox proportional hazard fashions with linear and cubic spline phrases have been used to evaluate associations.


A complete of 49 841 older adults (imply age, 67.19 [SD, 4.29] years; 54.7% have been feminine) have been adopted up for a imply of 6.72 years (SD, 0.95 years). Throughout this time, 414 people have been recognized with incident all-cause dementia. Within the absolutely adjusted fashions, there was a major nonlinear affiliation between time spent in sedentary conduct and incident dementia.

Relative to a median of 9.27 hours/d for sedentary conduct, the hazard ratios (HRs) for dementia have been 1.08 (95% CI, 1.04-1.12, P < .001) for 10 hours/d, 1.63 (95% CI, 1.35-1.97, P < .001) for 12 hours/d, and three.21 (95% CI, 2.05-5.04, P < .001) for 15 hours/d. The adjusted incidence fee of dementia per 1000 person-years was 7.49 (95% CI, 7.48-7.49) for 9.27 hours/d of sedentary conduct, 8.06 (95% CI, 7.76-8.36) for 10 hours/d, 12.00 (95% CI, 10.00-14.36) for 12 hours/d, and 22.74 (95% CI, 14.92-34.11) for 15 hours/d.

Imply day by day sedentary bout size (HR, 1.53 [95% CI, 1.03-2.27], P = .04 and 0.65 [95% CI, 0.04-1.57] extra dementia instances per 1000 person-years for a 1-hour improve from the imply of 0.48 hours) and most day by day sedentary bout size (HR, 1.15 [95% CI, 1.02-1.31], P = .02 and 0.19 [95% CI, 0.02-0.38] extra dementia instances per 1000 person-years for a 1-hour improve from the imply of 1.95 hours) have been considerably related to greater threat of incident dementia.

The variety of sedentary bouts per day was not related to greater threat of incident dementia (HR, 1.00 [95% CI, 0.99-1.01], P = .89). Within the sensitivity analyses, after adjustment for time spent in sedentary conduct, the imply day by day sedentary bout size and the utmost day by day sedentary bout size have been now not considerably related to incident dementia.

Conclusions and Relevance  

Amongst older adults, extra time spent in sedentary behaviors was considerably related to greater incidence of all-cause dementia. Future analysis is required to find out whether or not the affiliation between sedentary conduct and threat of dementia is causal.


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