Experts have long believed that exercise can help protect against dementia. However, although they noted a general pattern of risk reduction, studies on this topic have been small – and often conflicting – with little consensus on what type, frequency or intensity of exercise might be best.
“There is no real clear prescription that we can provide for physical activity,” said Dr. Joel Salinas, an assistant professor of neurology at New York University’s Grossman School of Medicine who specializes in treating people with dementia.
But three major long-term studies released in recent months have attempted to identify the types, intensity, and duration of physical activity that confer the most comprehensive protection against dementia. These studies, which have followed thousands or even hundreds of thousands of people for years at a time, confirm that regular physical activity, in many forms, plays a large role in reducing the risk of dementia.
Vigorous exercises seem to be best, but even unconventional exercises, such as doing housework, can provide a huge benefit. Surprisingly, it is equally effective in reducing the risk of dementia in those with a family history of dementia.
Many exercises can combat dementia.
In the The first studyPublished July 27 in the journal Neurology, researchers analyzed the health information of 501,376 participants without dementia in a British database called the UK Biobank to establish links between physical activity and risk of disease.
One of the main advantages of this database is that it contains “very rich data on genes” for the participants, said Dr. Huan Song, a researcher at West China Hospital, Sichuan University, who was one of the study’s authors. This included the participants’ risk profile based on whether they had genetic variants known to be associated with dementia, or whether they had immediate family members with the condition.
At the start of the study, participants filled out detailed questionnaires about their participation in physical activities, such as exercising, climbing stairs, or walking, and whether they regularly walked or cycled to go to work. They were also asked about various lifestyle factors, including how often they completed household chores.
One of the main obstacles to previous studies, Dr. Song said, is that the “definition of physical activity is too poor”. “Some use the total amount, others focus only on one style of activity.” British questionnaires provided privacy about the activities in which participants were participating on a regular basis.
The participants were followed for 11 years, during which 5,185 developed dementia. The study found that in participants who engaged in vigorous, regular activity, such as playing sports or exercising, the risk of developing dementia was reduced by 35 percent. Surprisingly, the people who reported completing household chores regularly also had a significant benefit; They had a 21 percent lower risk.
“Some people work very hard while they do housework,” said Dr. Sandra Weintraub, a neurologist at Northwestern University Feinberg School of Medicine, who was not associated with this study. “It could be that if you do chores for three hours, you’re as good as if you do 30 minutes of aerobic exercise.”
For Dr. Salinas, who recommends that people aim for 150 minutes of moderate to vigorous intensity exercise per week, the results reinforce the idea that moderate to vigorous exercise can boost brain health. Developing this exercise habit, he said, “is likely to have a very profound synergistic effect.” “You can get a lot of bang for your buck in terms of helping boost your health through physical activity.”
Perhaps most encouragingly, the association between physical activity and a reduced risk of dementia was extended to participants with a family history of dementia.
“It is very important to know that if you have a family history of dementia, you can use physical activity to reduce your risk,” said Dr. Song.
Start doing what you like best.
The second paperPublished last week in the journal Neurology, it pooled 38 studies to find out which recreational activities were associated with a reduced risk of dementia. In all, the studies followed more than two million participants without dementia over at least three years, during which time 74,700 developed dementia.
After controlling for age, education and gender, the researchers found that participants who exercised regularly — defined as participating in activities such as walking, running, swimming, dancing, participating in sports or exercising in the gym — had a 17 percent lower risk. developing dementia compared to those who did not.
This meta-analysis shows that dementia prevention is not limited to one activity, or even one type of activity. “We recommend people do the exercise they like,” said Li Shi, a researcher at Peking University and one of the study’s authors, because of the variety of physical activities participants engaged in.
When it comes to reaping the benefits of physical activity, it’s never too early to start. in The third study Published this month, researchers followed more than 1,200 children ages 7 to 15 for more than 30 years. Those with higher levels of physical fitness as children had higher levels of cognitive functioning in middle age, suggesting that establishing a habit of lifelong physical activity could be beneficial for brain health.
Together, these studies suggest that the ways we move our bodies on a daily basis can build up over time. They also reinforce the idea that regular, lifelong physical activity, in all its forms, goes a long way toward reducing the risk of dementia, even for people classified as high-risk.
Rachel Fairbank is a freelance science writer based in Texas.