Keeping senior citizens safe, healthy and happy longer is what we’re all about. We suggest a number of ways to do that from medical alert alarms to exercise programs.
Another study suggests that walking may prevent cognitive decline. Does that mean that walking 5 miles a week will keep your brain healthier? While the general consensus is that “exercise is good for you,” this type of study can only show a correlation between walking and healthier brains.
In order to prove that walking slows down mental decline, researchers would have to have a very large number of very similar individuals. They’d all have to be very much alike in lifestyle, genetic mix, age, socio-economic status, physical health, diet. That’s a very difficult thing to do. Difficult and expensive.
Next, researchers would have to break this large sample of the population into experimental and control groups. One group would be asked to walk 5 miles a week, another would be told to not walk very much and another would be free to do what they will. Each member of the study would have to be carefully monitored week by week for 10 years. That’s expensive and morally troubling.
How could medical researchers, who believe that walking is good for you, ask people to not walk? They couldn’t do it in good conscience.
Instead researchers use self-selected members; people who claim to be walkers or non-walkers. The trouble with this approach is that people who walk 5 miles a week may have an existing attribute that makes them want to and be able to walk so much. Folks who don’t walk may have existing medical conditions that make them unable to walk. These attributes or afflictions may be the real reason why their brains age differently.
This type of research is useful in identifying and proving correlations that can build the way towards more conclusive research.
The health benefits of regular walking can’t be denied. Walking helps preserve muscle tone, improves cardiovascular health, aids in weight loss, reducing cholesterol and keeps people busy and happy. Perhaps the brain boost comes from one or all of these factors. At any rate, it makes sense to start a walking program at any age.
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 today at the 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 and MCI, especially in areas of the brain’s key memory and learning centers,” said Cyrus Raji, Ph.D., from the Department of Radiology at the University of Pittsburgh in Pennsylvania. “We also found that these people had a slower decline in memory loss over five years.”
Alzheimer’s disease is an irreversible, progressive brain disease that slowly destroys memory and cognitive skills. According to the National Institute on Aging, between 2.4 million and 5.1 million Americans have Alzheimer’s disease. 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 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 3-D 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.”
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.
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 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.”
Coauthors are Kirk Erickson, Ph.D., Oscar Lopez, M.D., James Becker, Ph.D., Caterina Rosano, M.D., Anne Newman, M.D., M.P.H., H. Michael Gach, Ph.D., Paul Thompson, Ph.D., April Ho, B.S., and Lewis Kuller, M.D.
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Note: Copies of RSNA 2010 news releases and electronic images will be available online at RSNA.org/press10 beginning Monday, Nov. 29.
RSNA is an association of more than 44,000 radiologists, radiation oncologists, medical physicists and related scientists committed to excellence in patient care through education and research. The Society is based in Oak Brook, Ill. (RSNA.org)
Editor’s note: The data in these releases may differ from those in the printed abstract and those actually presented at the meeting, as researchers continue to update their data right up until the meeting. To ensure you are using the most up-to-date information, please call the RSNA Newsroom at 1-312-949-3233.