New research finds a link between physical activity and cognitive ability.
Researchers have long suspected that the more active a person is, the lower his or her risk of age-related cognitive decline and dementia, including Alzheimer’s disease. Studies have generally found good support for the relationship, but some rely on the participants to recall how active they’ve been. This method can be unreliable for a number of reasons, not the least of which is that people’s memories are not always dependable.
The people in the bottom 10 percent of intensity of activity were 2.8 times more likely to develop the disease as those in the top one percent of intensity level.
To avoid this issue, researchers in a recent study had 716 participants wear actigraphs on their wrists for 10 days so that their average activity levels could be calculated. Participants were an average of 82 years old when the study began and none was affected by cognitive decline. They took cognitive tests every year for an average of 3.5 years. At the end of the study period, 71 of the participants had been diagnosed with Alzheimer’s disease.
People who did the least amount of daily physical activity -- those in the bottom 10 percent -- were over twice as likely to have developed Alzheimer’s disease than people in the top 10 percent. The benefit of physical activity was even more pronounced for people who got some intense physical activity: The people in the bottom 10 percent of intensity of activity were 2.8 times more likely to develop the disease as those in the top one percent of intensity level.