Study Finds Type of Sitting Activity Influences Dementia Risk More Than Duration

Researchers have long warned that prolonged sitting increases the risk of dementia. However, a recent study reveals that the nature of the activity performed while sitting may be more significant than the length of time spent seated.

The study, published in the March issue of the American Journal of Preventive Medicine, found that replacing mentally passive sitting behaviors, such as watching television, with mentally active sitting activities like reading or office work, is linked to a substantially reduced risk of dementia.

The distinction between the two types of sitting is straightforward but critical: mentally active behaviors engage the brain during sitting, including reading, solving crosswords, and working on a computer. In contrast, passive behaviors involve activities like watching TV or scrolling passively through social media, which require minimal cognitive effort.

To reach these conclusions, Swedish researchers analyzed data from over 20,000 adults aged 35 to 64 and followed them for 19 years, from 1997 to 2016. Participants answered questions about their sitting habits, physical activity, and lifestyle, while dementia diagnoses were confirmed through Swedish health and mortality records.

The findings showed that individuals who engaged in mentally stimulating activities while sitting had a significantly lower likelihood of developing dementia compared to those who engaged in passive sitting behaviors.

Although the study was conducted in Sweden, the researchers assert that the results are applicable to a broader global population and could inform public health guidelines and preventive strategies aimed at reducing dementia risk.

Dr. Mats Hallgren, the lead researcher from the Karolinska Institute in Sweden, stated, "While all types of sitting involve similar energy expenditure, the level of brain activity during sitting makes the difference. How we use our brains while seated appears to be a crucial factor in future cognitive function and may predict the onset of dementia."

Hallgren added that sitting behavior is "a widespread but modifiable risk factor for many health conditions, including dementia. Our study adds that not all sitting behaviors are equal; some increase risk, while others may be protective. Therefore, it is important to remain physically and mentally active as we age, especially during periods of sitting."

This research emerges amid accelerating efforts to understand dementia. The Centers for Disease Control and Prevention (CDC) projects that approximately 14 million American adults will have Alzheimer's disease by 2060. Other recent studies have linked biological age to dementia risk and found that higher consumption of unprocessed meats may protect against dementia in older adults carrying certain genetic variants.