Many of us already spend several hours sitting each day, whether it be watching TV, playing games on our phones, driving a car, reading a book, or working from home or in the office.
Whatever activity you engage in while you sit matters, however, and it could affect your dementia risk, according to a new study published in the journal Proceedings of the National Academy of Sciences.
Researchers from the University of Southern California and the University of Arizona found older adults who sit for long periods of time while participating in passive and sedentary behaviors – such as watching television – may be at an increased risk of developing dementia.
The good news is that the study also highlighted that dementia risk can be lowered if people are active while sitting, like reading or using computers.
Dementia risk can be lowered if people are active while sitting, like reading or using computers.
“We found that time spent watching TV was associated with increased risk of developing dementia, while time spent using a computer was associated with decreased risk of dementia. Engaging in physical activity did not greatly alter these associations,” said David Raichlen, PhD, lead author of the study and professor of Biological Sciences and Anthropology at the University of Southern California.
He added the results remained the same even after they accounted for various levels of physical activity.
Raichlen and his colleagues analyzed more than 145,000 older adults aged 60 and older with no diagnosis of dementia. The participants were asked to self-report their levels of sedentary behavior. They also used data from the UK Biomedical databases of more than 500,000 people.
“Although this study cannot demonstrate causal links, we suggest that increasing cognitively engaging activities when sitting may have brain benefits,” Raichlen said. “Reducing passive activities like TV watching would be a good recommendation.”
Why might sedentary behaviors while sitting increase dementia risk?
According to Dr. Rebecca Lalchan, DO, movement disorder specialist at NYU Langone Hospital, sedentary behaviors while sitting (like watching TV) may be linked to higher dementia risk because muscles in the brain and body are not being used or actively worked.
“Passive tasks such as watching television or using social media do not challenge people’s attention, recall, ability to calculate or make associations,” Lachlan said. “This is likely similar to how our muscles can weaken and atrophy when we do not exercise.”
She added when people do not challenge their brain by doing brain exercises like puzzles or learning a new language, it’s possible that “certain networks such as memory can decline.”
Past research has shown that avoiding sedentary behaviors and adding light exercises, such as walking or grocery shopping, can reduce dementia risk by lowering cholesterol levels, reducing the risk of heart diseases, and strengthening bones and muscles.
“Sedentary lifestyle is very dangerous and has a broad range of negative health consequences, including a significant increase in the risk of developing dementia,” said Scott Kaiser, MD, a geriatrician with the Pacific Neuroscience Institute at Providence Saint John’s Health Center in Santa Monica, California. “So, it’s all about staying active and doing activities in many different forms.”
In addition, Raichlen said sedentary time is linked with low levels of muscle activity, which generally leads to detrimental physiological outcomes when sustained over long time periods. On the other hand, cognitive engagement may have brain benefits that can offset the negative impacts of sedentary time.
What are ways I can stay active while sitting down?
Beyond getting in some form of physical activity, there are some things caregivers can do to encourage their loved ones – especially those who may be bedridden or physically unable – to engage in more intellectual and cognitively stimulating/demanding activities while sitting. These may include:
- Reading a book, magazine or newspaper
- Drawing, painting or making artwork
- Listening to music or playing a musical instrument
- Learning a new language or skill
- Using light weights to do leg or arm exercises while sitting
- Flexing or extending wrists, elbows, shoulders and knees
- Playing games such as puzzles, sudoku, cards or chess
- Doing mindful activities such as meditating or journaling
- Socializing with other people via phone, video or in-person conversations
Lalchan said with social media and streaming networks, it can be easy for many of us to become sedentary. That’s why she recommends people step away from the screens and interact with each other, specifically the older adults in our lives, to exercise our brains.
“Find something they enjoy doing, even if it’s sitting outside and observing. Practice it daily, and eventually it will become a habit,” Lalchan added.
Raichlen noted that more intervention studies will be needed to prove causal links between behaviors and outcomes.
“The main take-home message is that this study forms a foundation for further examining what we do when we are sitting as a way to help reduce the risk of developing dementia later in life,” he said.