U. PITTSBURGH (US) — Walking may slow cognitive decline in adults with mild cognitive impairment (MCI) and Alzheimer’s disease, according to a new study.
“We found that walking five miles per week protects brain structure over 10 years in people with Alzheimer’s and MCI, especially in areas of the brain’s key memory and learning centers,” says Cyrus Raji, who is in the combined M.D./Ph.D. program at University of Pittsburgh.
“We also found that these people had a slower decline in memory loss over five years.”
The study was to be presented today at the annual meeting of the Radiological Society of North America in Chicago.
Alzheimer’s disease is an irreversible, progressive brain disease that slowly destroys memory and cognitive skills, affecting between 2.4 million and 5.1 million Americans. Based on current population trends, that number is expected to increase significantly over the next decade.
In cases of MCI, a person has cognitive or memory problems exceeding typical age-related memory loss, but not yet as severe as those found in Alzheimer’s disease. About half of the people with MCI progress to Alzheimer’s disease.
“Because a cure for Alzheimer’s is not yet a reality, we hope to find ways of alleviating disease progression or symptoms in people who already are cognitively impaired,” adds Raji.
For the ongoing study, the researchers 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), composed of 83 adults with MCI and 44 adults with Alzheimer’s dementia.
Researchers monitored how far each of the patients walked in a week. After 10 years, all patients underwent 3-D MRI exams to identify changes in brain volume, which is a vital sign for the brain, notes Raji.
“When it decreases, that means brain cells are dying. But when it remains higher, brain health is being maintained.”
In addition, patients were given the mini-mental state exam (MMSE) to track cognitive decline over five years. Physical activity levels were correlated with MRI and MMSE results. The analysis adjusted for age, gender, body fat composition, head size, education, and other factors.
Across the board, 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 is a devastating illness, and unfortunately, walking is not a cure,” adds Raji. “But walking can improve your brain’s resistance to the disease and reduce memory loss over time.”
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