The brain structure in individuals with Alzheimer’s and mild cognitive impairment (MCI) was protected by walking just five miles a week over 10 years, particularly in the learning and memory centers of the brain. Over five years, these individuals also had a slower decline in memory loss.
Alzheimer’s is a progressive and irreversible brain disease which slowly destroys cognitive and memory skills. Approximately 2.4 to 5.1 million Americans have Alzheimer’s, and according to current population trends, this amount is likely to significantly increase over the next 10 years.
With MCI, an individual has memory or cognitive problems beyond typical age-related loss of memory, but not yet as severely as that seen in Alzheimer’s. Approximately 50% of individuals with MCI progress to Alzheimer’s.
The relationship between brain structure and physical activity was analyzed in 426 individuals for the 20-year study, which included 299 healthy individuals with an average age of 78, and 127 cognitively impaired individuals with an average age of 81, which included 44 individuals with Alzheimer’s and 83 individuals with MCI.
Each individual was monitored how far they walked in a week. All individuals had 3-D MRI exams after 10 years to identify brain volume changes. Brain cells are dying when brain volume decreases, and brain health is being maintained when brain volume remains higher.
Individuals were also given the MMSE (mini-mental state exam) to follow cognitive decline over 5 years. MMSE and MRI results were correlated with physical activity levels. The analysis adjusted for gender, age, head size, education, body fat composition as well as other factors.
The results revealed that greater brain volume was linked to greater amounts of physical activity across the board. Cognitively impaired individuals had to walk approximately 5 miles, or 58 city blocks, a week to slow cognitive decline and maintain brain volume.
Healthy individuals had to walk approximately 6 miles, or 72 city blocks, a week to maintain brain volume and reduce cognitive decline risk significantly.
MMSE scores decreased on average by 5 points in cognitively impaired individuals who didn’t engage in an adequate level of physical activity over 5 years, in comparison to a decrease of only 1 point in individuals who met the required physical activity.
Although walking isn’t a cure for Alzheimer’s, it can help the brain to resist the disease and reduce long term memory loss.