Can Exercise Prevent Alzheimer’s Disease?
According to the Alzheimer’s Association, an estimated 5.8 million Americans of all ages were living with Alzheimer’s-type dementia in 2019. This number includes an estimated 5.6 million people ages 65 and older, and approximately 200,000 individuals under age 65 who have younger-onset Alzheimer’s.
One in 10 people age 65 and older (i.e., 10 percent) has Alzheimer’s dementia. It is the most common form of dementia, accounting for 60 percent to 80 percent of cases in the U.S.
Our primary care doctors in Delray Beach know how terrifying the possibility of developing this disease is to anyone who is approaching middle age, or who is older and may be experiencing memory lapses that could indicate Alzheimer’s.
Alzheimer’s is a progressive brain disease that eventually robs sufferers of their memory and thinking skills, impacting their ability to perform everyday tasks. There is no proven cure for the disease, including so-called “memory pills” advertised heavily on television.
Exercise is medicine
Now, new research from the U.S. Department of Veteran’s Affairs (VA) in Washington and George Washington University has confirmed what previous studies have demonstrated: The more physically fit you are, the less likely you are to develop Alzheimer’s.
For this study, researchers tested and tracked nearly 650,000 veterans, with an average age of 61, for nearly 10 years. Participants were divided into five groups depending on their cardiorespiratory fitness levels, from lowest to highest. Cardiorespiratory fitness is defined by how well the body transports oxygen to muscles, and how well muscles are able to absorb that oxygen.
They found that the risk of Alzheimer’s decreased between 13 percent in those who were determined to be slightly more fit than the first group (who never exercised) to 33 percent in those with the highest level of cardiorespiratory fitness.
“One exciting finding of this study is that as people’s fitness improved, their risk of Alzheimer’s disease decreased—it was not an all-or-nothing proposition,” study author Edward Zamrini, MD, of the Washington VA Medical Center, said in a statement.
“So people can work toward making incremental changes and improvements in their physical fitness and hopefully that will be associated with a related decrease in their risk of Alzheimer’s years later,” he said.
Every little bit helps
That finding has been shown in other studies, as well. For example, a 2020 study examined data on nearly 250,000 people in their mid- to late 60s with mild cognitive impairment. The researchers found that those who exercised for as little as 10 minutes a day before and after their diagnosis slowed their risk of progression to Alzheimer’s by 18 percent.
Even more surprising, those who didn’t start exercising until after being diagnosed were still able to reduce the risk of progression by 11 percent. On the other hand, those who stopped exercising after their diagnosis appeared to once again increase their risk of progression.
“There are currently no approved [Alzheimer’s] disease-modifying treatments, and lifestyle modifications have become an important strategy to prevent its progression,” the study authors wrote.
“Physical activity is considered to be the most important interventional strategy for the prevention of dementia,” they said.
Even in those with severe dementia, just one hour of exercise twice a week improved subjects’ cognitive decline, according to another study of those with moderate to severe Alzheimer’s that was published in the Journal of the American Geriatrics Society.
What’s the connection?
“Exercise is important for the brain because it floods the brain with an increased fresh supply of blood, clearing out harmful waste products and providing it with the nutrients it needs to function,” according to the Alzheimer’s Organization, a group founded by medical professionals.
The organization explains that there are many benefits of exercise for the brain. First, the increased blood flow allows the brain to perform at a higher level. It also creates more cells and produces more protective chemicals that help prevent brain damage.
In addition, repeated bouts of exercise strengthen the heart, allowing it to more efficiently pump more blood to all parts of the body, including the brain. As the brain becomes accustomed to the increased fuel and nutrients, it begins to create more protective chemicals and remove more of the harmful ones.
Finally, according to the Mayo Clinic, regular physical activity also helps counteract some of the natural reduction in brain connections that occurs with aging.
How much is enough?
The World Health Organization (WHO) recommends 150 minutes of moderate-intensity aerobic physical activity (e.g. brisk walking, dancing, gardening, water aerobics) or 75 minutes of vigorous-intensity physical activity (e.g., jogging, running, jumping rope, swimming laps) every week.
But as we’ve shown, any exercise is better than none. It also helps with flexibility, balance, and endurance, improves mood, boosts energy, and helps ward off numerous diseases, including heart disease, cancer, and type 2 diabetes.
Just be sure to check with us before beginning a new exercise program. And if you’re concerned about new or worsening symptoms of memory problems, please let us know.