It’s no secret that exercise has many benefits. For example, we previously reported on a study that found that regular physical activity reduced the risk of more than 200 diseases—even when it was squeezed into a couple of days as opposed to spreading it throughout the week. Included among those 200 diseases was dementia.
Dementia is an umbrella term for a condition that affects someone’s ability to think, remember and make decisions in everyday life. Alzheimer’s disease is the most common type of dementia, accounting for 60% to 80% of all dementia cases. Unfortunately, dementia is on the rise in America—approximately 6.7 million U.S. adults have Alzheimer’s disease and that number is expected to double by the year 2060.
While dementia is incurable, it may be preventable (or at the very least, it can be slowed down and delayed). Exercise is one of the health habits that can help—and a new study suggests that just a few minutes each week can help more than you may realize. Researchers at Johns Hopkins Bloomberg School of Public Health set out to try to clear up some of the unknowns. They published their findings in the Journal of the American Medical Directors Association. Here’s what they found and how you can apply their findings to your life.
How Was This Study Conducted?
Researchers pulled data from the UK Biobank, a large, long-running study in the United Kingdom that collects data from over 500,000 people. The information includes demographics—including age, sex, socioeconomic status and education level—and health information—like blood pressure, cholesterol levels, BMI and medical history.
Participants were voluntarily recruited into the UK Biobank between 2006 and 2010. The purpose of the Biobank is to help advance modern medicine and foster a deeper understanding of disease prevention, diagnosis and treatment.
Between February 2013 and December 2015, a subsample of 106,053 participants accepted the invitation to wear an accelerometer on their wrist for seven days. An accelerometer is similar to a smartwatch and tracks all activity, including how vigorous it is and for how long. The information gathered from the accelerometers was recorded in the Biobank.
For this current study, researchers chose 89,667 of the 106,053 accelerometer participants who met their criteria. At the time they wore the accelerometer, the average age of the participants was 63; 56% were women and 59% of the total participants reported no chronic disease or frailty. These participants were followed for just over four years on average. During that time, 735 of them were diagnosed with dementia.
In addition to the accelerometer data, they also collected demographic and medical information for the almost 90,000 participants. This included diagnoses of both dementia and frailty.
Frailty is based on five factors: low hand-grip strength, slow walking speed, unintentional weight loss, self-reported exhaustion and low self-reported physical activity. Participants were then labeled as being robust (0 factors for frailty), prefrail (1 to 2 factors for frailty) or frail (3 or more factors). The reason frailty was observed is because it’s associated with a higher risk of dementia. Plus, people experiencing frailty tend to be less active.
The primary aim of this study was to evaluate the minimum amount of moderate-to-vigorous physical activity (MVPA) to reduce the risk of dementia. A secondary goal of this study was to assess whether the association between MVPA and dementia differed based on frailty status.
What Did This Study Find?
Several statistical analyses were run, including adjusting for certain confounding factors (like the demographics). Researchers found that compared to those with no MVPA:
- Engaging in one to 35 minutes of MVPA per week was associated with a 41% reduced risk of dementia
- Engaging in 36 to 70 minutes of MVPA per week was associated with a 60% lower risk of dementia
- Engaging in 71 to 140 minutes of MVPA per week was associated with a 63% reduced risk of dementia
- Engaging in more than 140 minutes of MVPA per week was associated with a 69% decreased risk of dementia
When considering frailty status, researchers found no difference between those labeled robust and those labeled frail.
“This suggests that even frail or nearly frail older adults might be able to reduce their dementia risk through low-dose exercise,” says Amal Wanigatunga, Ph.D, M.P.H., one of the lead study authors and an assistant professor in the John Hopkins Bloomberg School’s Department of Epidemiology, in a press release.
How Does This Apply to Real Life?
These study authors note that the official physical activity guidelines endorsed by the Department of Health and Human Services—at least 150 minutes of moderate physical activity per week or 75 minutes of vigorous physical activity per week—are unattainable for some people, including those who are frail.
However, this study suggests that anything more than one minute of moderate-to-vigorous physical activity has some benefits regarding dementia prevention. In other words, every little bit counts.
This concept may be difficult if you struggle with an all-or-nothing mindset. If you’re the kind of person who might give up on working out for the day if you don’t have time to do your full workout routine, try to let go of that habit. Just because you can’t get in a full hour or 30 minutes at the gym doesn’t mean it’s not worth exercising in the little time you do have. Having such a fixed mindset may eventually show up as unbelief in your ability to prevent disease or to exercise properly.
Does that sound familiar?
When implementing any new habit, it’s important to begin with where you’re at. Sounds like common sense, but so many of us try to start at the end goal—which usually ends up in quickly burning out.
Using physical activity as an example, if you’re currently averaging way under the recommended 150 minutes of moderate physical activity per week but you decide to start there—say, by walking 20 to 25 minutes every day—you might last a few days and most likely will quickly resort to old habits. It’s not your fault. It’s just how our brains work.
But if your goal is to hit that 150 minutes a week and you start with something smaller—like a 15-minute walk three times a week—and slowly increase from there, you’re more likely to meet your goal over time.
The good news is that this isn’t the only study to suggest that there are benefits to moving in smaller amounts than the guidelines recommend. Another study we reported on suggests that climbing 60 to 100 steps a day—about four to eight flights of household stairs—can significantly reduce your risk of heart attack and stroke. This can be done by intentionally being less efficient. For example, instead of carrying the entire laundry basket upstairs, take just a few items at a time to get more stairs in.
How about the study that suggests exercising just once a week can reduce your diabetes risk? These examples show that little changes to your routine can really make a difference in the long run.
So, yes, many studies show that for disease prevention, you will enjoy some protection with almost any amount of physical activity—because it’s about the cumulative effect over time. It’s important to note, however, that while it doesn’t take much physical activity to reduce disease risk, if you want to improve your fitness level you need to engage in a higher amount of physical activity.
The Bottom Line
This study suggests that any amount of physical activity may help reduce the risk of dementia, regardless of the level of frailty. You can get a head start on preventing dementia by making physical activity a habit now, since changes in the brain leading to Alzheimer’s begin decades before symptoms show up. Besides physical activity, we also know that an anti-inflammatory diet that includes plenty of fiber, healthy fats and antioxidants also contributes to reduced dementia risk, as does getting plenty of quality sleep, managing your stressors and spending time with family and friends.
