Sitting all day? How to reduce your risk of dementia

They say sitting is the new smoking. While that warning isn’t entirely wrong, it may not tell the whole story. Not all sitting is treated equal. New research suggests that what you do while sitting also matters.

A new study published in the American Journal of Preventive Medicine has examined the difference between passive and mentally active sitting in relation to dementia. What they found was striking.

What you do while sitting matters

The researchers found that not all sedentary behaviors are equal when it comes to dementia risk. Adults who spend long periods in mentally passive activities like watching TV have a higher risk of dementia. The researchers also noted that replacing such passive activities with mentally active sedentary behaviors, such as reading a book, may reduce the risk of dementia onset in later life.

Dementia a rising health concern

As populations are aging globally, dementia is becoming a rising concern. Dementia is the third-highest cause of mortality. It is the seventh largest cause of disability among older adults globally. These age-related conditions affect the quality of life, and hence, prevention is crucial. And that’s where identifying modifiable risk factors is important.

Sedentary behavior and dementia risk

Earlier, it was thought that all kinds of sedentary behaviors were associated with a higher risk of developing dementia. However, in recent studies, it was found that mentally passive sedentary behaviors (such as watching TV) increased the risk of depression, while mentally active sedentary behaviors (such as reading and office work) appeared to be protective!Nowadays, most adults spend about 9-10 hours per day sitting.

Mounting evidence has connected this extended, uninterrupted sitting to a risk factor for cardiovascular disease, type 2 diabetes, and depression. This sedentary lifestyle is also related to dementia. Researchers of this study are the first to explore the distinction between passive and mentally active sitting in association with dementia.“While all sitting involves minimal energy expenditure, it may be differentiated by the level of brain activity.

How we use our brains while we are sitting appears to be a crucial determinant of future cognitive functioning and, as we have shown, may predict dementia onset,” lead investigator Mats Hallgren, PhD, Department of Public Health Sciences, Karolinska Institute, Sweden, and Baker-Deakin Department of Lifestyle and Diabetes, Institute for Physical Activity and Nutrition (IPAN), Deakin University, Australia, said in a release.

The researchers analyzed data from a longitudinal study of 20,811 adults aged 35-64 years followed over 19 years (1997-2016). The participants took a survey where they were asked about their sedentary behaviors, physical activity, and other behaviors associated with dementia. They also identified cases of dementia by linking data from the 1997 survey with national records, including the Swedish National Patient Register and the Swedish Cause of Death Register.

The researcher examined the associations with dementia of (statistically) substituting passive with mentally active sedentary behaviors.

Passive sitting vs mentally active sitting

What they discovered is groundbreaking. The researchers found that entirely active sedentary behavior was associated with a reduced risk of developing dementia among middle-aged and older adults. They also found that increasing time spent in mentally active sedentary behavior was associated with a significant reduction in dementia risk, even when levels of passive sitting and physical activity remained the same.The researchers observed that replacing the amount of time spent in mentally passive sedentary behavior with equal duration of mentally active sedentary behavior was also associated with a reduction in the risk for developing dementia.“The prospective study design allowed us to establish the direction of these relationships and infer but does not establish causality. Controlled trials are needed to confirm these important observational study findings,” Dr.

Hallgren said. “Sedentary behavior is a ubiquitous but modifiable risk factor for many health conditions, including dementia. Our study adds the observation that not all sedentary behaviors are equivalent; some may increase the risk of dementia, while others may be protective. It is important to remain physically active as we age, but also mentally active—especially when we are sitting,” the researcher added.