Global increase in dementia
A recent report that used data from the Global Burden of Diseases, Injuries, and Risk Factors Study in 2019 estimated that the number of people with dementia would increase globally from 57.4 million in 2019 to 130.8 million in 2050. The estimated increase varied widely among regions with the lowest in high-income Asia-Pacific countries (53 percent increase) and the highest in North Africa and the Middle East (367 percent increase).
Middle-agers can avoid or postpone dementia
The global increase in the prevalence of dementia hangs like a dark cloud over humanity. Yet, longitudinal studies show connections between increased physical activity and reduced risk of dementia. However, as of 2021, all but one of these studies used self-reported physical activity, which can reflect recall bias. Researchers used objective physical activity data from wrist-worn devices for 84,854 participants with an average age of 62 years in the UK Biobank Study to determine if a dose-response relationship existed between increased physical activity and reduced risk of dementia. Compared to participants with the lowest category of physical activity, participants in categories of increasing physical activity had significant and progressively lower risk of all-cause dementia, Alzheimer’s dementia, and vascular dementia over an average follow-up of 6 years.
The highest level of physical activity (equivalent to 57 minutes or more of brisk walking per day) predicted a significant 84 percent lower risk of all-cause dementia compared to the lowest level (equivalent to 14 minutes of brisk walking per day). Even the next level up (equivalent to 14-28 minutes of brisk walking per day) from the lowest level predicted a significant 48 percent lower risk of developing all-cause dementia. Alzheimer’s and vascular dementia showed similar results.
Participants in the highest category of physical activity (about 1 hour per day) postponed the diagnosis of Alzheimer’s dementia by 9.2 years and 12.3 years for vascular dementia by 12.2 years. Wow! This study offers two key messages: 1) Even a mere half-hour of brisk walking per day may lower your risk of dementia. 2) One hour of daily brisk walking may greatly reduce your risk of dementia and postpone it for a decade or more. Can’t you find time in your life for 1 hour of brisk walking every day? For your own sake? For you loved ones’ sake?
Increase your daily steps
Having a daily step goal can help you get enough physical activity to enjoy better health. Could getting plenty of daily steps reduce your risk of dementia? Researchers in Australia used data from 78,430 participants with an average of 61 years in the UK Biobank to find out. The number of steps per day was determined objectively from wrist-worn accelerometers. During a median follow-up of 7 years and compared to participants in the lowest category of daily steps (1,540-5,386), participants with 9,826 steps per day had the lowest (51 percent lower) relative risk of developing dementia. Participants who achieved an average peak walking cadence of 112 steps per minute for 30 minutes per day had 62 percent lower risk. Even minimal numbers of steps per day lowered the risk of developing dementia. These impressive results accounted for confounding factors, such as age, education, and socio-economic status. If you have a goal of 10,000 daily steps, you may greatly reduce your risk of dementia for which there is currently no cure. You can do even better by walking at a brisk pace.
Measured physical activity and daily steps for octogenarian women
The prevalence of dementia in the US is expected to double from about 5 to 10 million cases between 2019 and 2050. Women are about twice as likely as men to develop dementia. Higher amounts of physical activity predict lower risk of dementia, yet many of the existing studies rely on self-reported rather than objectively measured physical activity. Researchers remedied this shortcoming with accelerometer-measured physical activity and sedentary behavior data from 1,277 participants with an average of 82 years in the Women’s Health Initiative Study. After adjusting for confounding factors and compared to women in the lowest quartile of moderate to strenuous physical activity (less than 23 minutes per day), women in the highest quartile (61 or more minutes per day) had 31 percent lower risk of developing mild cognitive impairment or probable dementia during 4 years of follow-up. Each 31 minute per day increase in moderate to strenuous physical activity predicted a 20 percent decline in risk mild cognitive impairment or probable dementia.
When physical activity was measured as steps per day, the results were even more impressive. Compared to women in the lowest quartile of steps per day (less than 1,867), women in the highest quartile of steps per day (4,050 or more) had 62 percent lower risk of developing mild cognitive impairment or probable dementia during follow-up. Neither sitting time nor light-intensity steps per day predicted lower risk of mild cognitive impairment or probable dementia. Steps per day is an easy concept for older people to grasp and measure with wearable devices. Why not get one and keep track of your daily steps?