With commentary by lead study author Clinton Wright, MD, chief of the division of cognitive disorders at the Leonard M. Miller School of Medicine, University of Miami.
There’s a growing body of evidence that the best way to help prevent the age-related decline in your cognitive abilities is to exercise. This could be especially beneficial to people with diabetes, who are at higher risk of cognitive decline.
A new study, published in the online issue of Neurology, has looked at broader measures of cognitive function in a very diverse group of older adults, including a high number of African American and Latino adults. The vast majority—90 percent—were not regular exercisers.
The researchers looked at the exercise reports of 876 adults 65 and older. They were followed up five years later and given memory and cognitive tests as well as a brain MRI. The researchers found that older adults who reported no to light exercise at the outset of the study experienced a greater decline in cognitive abilities such as executive function, semantic memory, and processing speed than those who reported moderate to intense exercise. “The degree of decline was equivalent to the expected decline associated with approximately 10 years of cognitive aging,” the authors wrote. Moderate to intense exercise included running, aerobics or calisthenics.
“The association in this study suggest that moderate to heavy physical activity is good and seems to apply even in this diverse population,” says the study’s lead author Clinton Wright, MD, chief of the division of cognitive disorders at the Leonard M. Miller School of Medicine, University of Miami. “The strength of this study is that it’s a large observational study from an ethnically and racially diverse group. Past studies have focused on largely white populations, and they were smaller and not a random sample.”
Exercise is believed to protect the brain against gaining in a number of ways. Physical activity helps to maintain healthy blood vessels and blood flow to the brain. It helps reduce cardiovascular risk factors, such as diabetes, hypertension, and obesity, which can all cause cerebrovascular events like mini strokes and strokes. Some studies show that exercise may affect several biological processes involved in cognition such as angiogenesis (creating new blood vessels), neurogenesis (creating new neurons), and improving the connection between neurons.
Though this study did not focus on how much exercise you need to do and how intensely you have to exercise, it clearly showed that moderate to intense exercise is the most effective. This dovetails with current advice that having shorter but more intense workouts is more effective than, say, long leisurely walks around the neighborhood. The moderate and intense physical activities include running, swimming, tennis, and aerobics or calisthenics. “Engaging in these on a relatively frequent basis for enough time to get your heart rate up is probably more beneficial than going for a long walk, at least according to this data,” says Wright. As an older adult, you can do interval training with low impact routine like squats, sit ups, and wall push ups, and still get your heart rate up. A few studies have found cognitive benefits among older people who lifted weights for a year and did not otherwise exercise.
But any exercise is better than none. Studies have shown that if you are sedentary and just starting to exercise, you will see benefits by even light exercising.