Walking five miles per week was shown to improve the brain’s resistance to Alzheimer’s disease and mild cognitive impairment and reduce memory loss over time.
CHICAGO—Walking may slow cognitive decline in adults with mild cognitive impairment (MCI) and Alzheimer’s disease, as well as in healthy adults, according to a study presented at the 96th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA).
“We found that walking five miles per week protects the brain structure over 10 years in people with Alzheimer’s disease and MCI, especially in areas of the brain’s key memory and learning centers,” said Cyrus Raji, PhD.
“We also found that these people had a slower decline in memory loss over five years.” Dr. Raji is from the Department of Radiology at the University of Pittsburgh.
“Because a cure for Alzheimer’s disease is not yet a reality, we hope to find ways of alleviating disease progression or symptoms in people who are already cognitively impaired,” Dr. Raji said.
For the ongoing 20-year study, Dr. Raji and colleagues analyzed the relationship between physical activity and brain structure in 426 people, including 299 healthy adults (mean age, 78) and 127 cognitively impaired adults (mean age, 81), including 83 adults with MCI and 44 adults with Alzheimer’s dementia. Patients were recruited from the Cardiovascular Health Study. The researchers monitored how far each of the patients walked in a week. After 10 years, all patients underwent 3D MRI exams to identify changes in brain volume.
“Volume is a vital sign for the brain,” Dr. Raji said. “When it decreases, that means brain cells are dying. But when it remains higher, brain health is being maintained.”
Brain Volume Maintained, Cognitive Decline Slowed
In addition, patients were given the Mini-Mental State Examination (MMSE) to track cognitive decline over five years. Physical activity levels were then correlated with MRI and MMSE results. The analysis adjusted for age, gender, body fat composition, head size, education, and other factors.
The findings showed across the board that greater amounts of physical activity were associated with greater brain volume. Cognitively impaired people needed to walk at least 58 city blocks, or approximately five miles, per week to maintain brain volume and slow cognitive decline. The healthy adults needed to walk at least 72 city blocks, or six miles, per week to maintain brain volume and significantly reduce their risk for cognitive decline.
Over five years, MMSE scores decreased by an average of five points in cognitively impaired patients who did not engage in a sufficient level of physical activity, compared with a decrease of only one point in patients who met the physical activity requirement.
“Alzheimer’s disease is a devastating illness, and unfortunately, walking is not a cure,” Dr. Raji said. “But walking can improve your brain’s resistance to the disease and reduce memory loss over time.”