Dementia appears to be a growing problem, with someone in the world developing dementia every three seconds. Additional stats show that an estimated 6.7 million older adults in the United States have Alzheimer’s disease (a type of dementia). That number is expected to double by 2060. While many risk factors you can’t control come into play, such as genetics and family history, there’s one you can change. And that’s having a sedentary lifestyle.
Most people spend a large portion of their day sitting. In fact, research has shown that nearly one-third (31%) of the world’s adult population, 1.8 billion people, are physically inactive. We sit to commute to work, sit at a desk while working, during meals and then some more at night to unwind with our favorite TV show or mindless screen time. Staying physically active not only helps reduce your risk of dementia but also improves sleep, strengthens bones and reduces the risk of anxiety, to name a few.
In this article, you’ll learn from three neurologists how a sedentary lifestyle may influence your risk of dementia, and get their tips on what can improve your brain health.
How a Sedentary Lifestyle Increases Your Risk of Dementia
“Studies show an association between all types of dementia and sedentary behavior. A definitive correlating causal risk has not been determined. However, we do know that doing passive activities such as watching TV or sitting for a prolonged period of time uninterrupted can lead to decreased blood flow in the brain. Further, sedentary behavior could potentially impair glucose and lipid metabolism, two other risk factors for developing dementia,” says Jigar Rathod, M.D., a neurologist at Memorial Hermann Mischer Neuroscience Associates.
The impact of sedentary behavior on the brain occurs through various pathways. “Sedentary behavior reduces blood flow to the brain, increases the risk of cardiovascular and related diseases (diabetes, hypertension, obesity), causes brain structure changes, and increases inflammation and insulin resistance,” explains Verna R. Porter, M.D., a board-certified neurologist and director of Dementia, Alzheimer’s Disease and Neurocognitive Disorders at Pacific Neuroscience Institute at Providence Saint John’s Health Center in California.
Reduced Blood Flow to the Brain
Reduced or interrupted blood flow to the brain impairs the delivery of nutrients and oxygen. In fact, vascular dementia is a type of dementia caused by different conditions that interrupt the flow of blood and oxygen supply to the brain. “A sedentary lifestyle leads to decreased cerebral blood flow, increasing the risk of neurodegeneration. Physical activity, on the other hand, enhances circulation, which delivers oxygen and nutrients essential for brain health,” notes Porter.
Increased Risk of Cardiovascular and Related Conditions
Physical activity can improve cardiovascular health, contributing to better blood pressure, cholesterol and blood sugar. Many people don’t realize that heart health and brain health are connected, says Porter: “A sedentary lifestyle contributes to hypertension, obesity and diabetes or even sleep apnea—all of which are significant dementia risk factors,” she adds.
Changed Brain Structure
In an older observational study that examined physical activity and brain volume, researchers found that hippocampal atrophy was associated with leisure-time physical inactivity. “Prolonged inactivity can lead to brain atrophy (loss of brain volume), particularly in areas like the hippocampus, which is crucial for memory,” notes Porter.
Increased Chronic Low-Grade Inflammation
Chronic low-grade inflammation is associated with an increased risk of many conditions, including dementia. “This type of inflammation is exacerbated by inactivity and contributes to the buildup of beta-amyloid plaques and tau tangles, which are biomarkers of Alzheimer’s disease,” says Porter. Regular physical activity is associated with decreased inflammation and can help you keep your thinking, learning and judgment skills sharp as you age.
Tips for Decreasing Your Risk of Dementia
Some risk factors for dementia, like age, family history and genetics, are not modifiable. Still, many lifestyle modifications, such as the ones below, can reduce risk.
- Take Breaks from Sitting: Moving more doesn’t mean you have to spend hours at the gym. Studies show that even a small amount of walking, 15 to 30 minutes one or two times per week, is associated with a decreased risk of dementia compared to those who are not physically active. And walking isn’t the only way to reap the benefits. Rathod shares that doing chores around the home, like vacuuming and sweeping or taking the stairs instead of an elevator if you can, counts as movement. The more movement you get in throughout your day, the better!
- Play Games (Brain-Stimulating Ones) with Others: “Cognitive games, crossword puzzles, word searches and games on the computer/phone are helpful for reducing dementia risk. Board games are also of great benefit as they allow social interaction,” says Rathod. “These types of games can build cognitive resilience,” notes Porter. Additionally, “Socialization is a great whole brain–stimulating activity that would perhaps reduce dementia risk in the same way as exercise and movement,” adds Douglas Scharre, M.D., a neurologist and clinical professor at the Center for Cognitive and Memory Disorder at The Ohio State University Wexner Medical Center.
- Avoid Smoking and Reduce Alcohol: Smoking is a vascular risk factor that can increase dementia risk. “Smoking damages blood vessels, leading to reduced oxygen flow to the brain, while excessive alcohol accelerates cognitive decline and has neurotoxic properties,” says Porter.
- Get Regular Checkups: Your brain health is connected to your physical health. “Conditions like hypertension, diabetes and high cholesterol significantly increase dementia risk,” notes Porter. She recommends monitoring and managing these conditions with regular doctor visits and lifestyle modifications.
- Eat More Brain-Healthy Foods: The MIND diet, a hybrid of the Mediterranean and DASH diets, was created to improve brain health. Research has shown that following this dietary pattern may be associated with a lower risk of dementia. Some foods the MIND diet encourages you to eat are fruits, vegetables, whole grains, nuts, seeds, and omega-3-rich foods such as salmon and mackerel.
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The Bottom Line
The prevalence of dementia has increased in recent years and, unfortunately, it doesn’t seem to be stopping anytime soon. The good news is that some habits, like moving more and sitting less, can help reduce your risk.
A little movement can go a long way. Start small and build your way up to the recommended 150 minutes of moderate-intensity weekly exercise. Remember that all types of physical activity count, so make them enjoyable.
Alongside movement, consider playing brain-stimulating games, engaging in social conversations and activities and getting regular checkups. Lastly, fuel your brain with nourishing brain foods, such as those emphasized on the MIND diet.