exercise Alzheimer's

How exercise may protect against Alzheimer's

February 8, 2019

Science Daily/Columbia University Irving Medical Center

A hormone called irisin -- produced during exercise -- may protect neurons against Alzheimer's disease.

 

Athletes know a vigorous workout can release a flood of endorphins: "feel-good" hormones that boost mood. Now there's evidence that exercise produces another hormone that may improve memory and protect against Alzheimer's disease, according to a study co-led by Ottavio Arancio, MD, PhD, a researcher at Columbia University's Vagelos College of Physicians and Surgeons and Taub Institute for Research on Alzheimer's Disease and the Aging Brain.

 

The study was published in Nature Medicine.

 

Physical activity is known to improve memory, and studies suggest it may also reduce the risk of Alzheimer's disease. But researchers don't understand why.

 

A few years ago, exercise researchers discovered a hormone called irisin that is released into the circulation during physical activity. Initial studies suggested that irisin mainly played a role in energy metabolism. But newer research found that the hormone may also promote neuronal growth in the brain's hippocampus, a region critical for learning and memory.

 

"This raised the possibility that irisin may help explain why physical activity improves memory and seems to play a protective role in brain disorders such as Alzheimer's disease" says Arancio, who is a professor of pathology and cell biology and of medicine at Columbia University Vagelos College of Physicians and Surgeons.

 

Irisin is reduced in brains of people with Alzheimer's

 

In the new study, Arancio and his colleagues at the Federal University of Rio de Janeiro in Brazil and Queens University in Canada first looked for a link between irisin and Alzheimer's in people. Using tissue samples from brain banks, they found that irisin is present in the human hippocampus and that hippocampal levels of the hormone are reduced in individuals with Alzheimer's.

 

To explore what irisin does in the brain, the team turned to mice. These experiments show that irisin, in mice, protects the brain's synapses and the animals' memory: When irisin was disabled in the hippocampus of healthy mice, synapses and memory weakened. Similarly, boosting brain levels of irisin improved both measures of brain health.

 

Swimming boosts irisin, protects memory in mice

 

The researchers then looked at the effect of exercise on irisin and the brain. In the study's most compelling experiments, the researchers found that mice who swam nearly every day for five weeks did not develop memory impairment despite getting infusions of beta amyloid -- the neuron-clogging, memory-robbing protein implicated in Alzheimer's.

 

Blocking irisin with a drug completely eliminated the benefits of swimming, the researchers also found. Mice who swam and were treated with irisin-blocking substances performed no better on memory tests than sedentary animals after infusions with beta amyloid.

 

Together the findings suggest that irisin could be exploited to find a novel therapy for preventing or treating dementia in humans, Arancio says. His team is now searching for pharmaceutical compounds that can increase brain levels of the hormone or can mimic its action.

 

"In the meantime, I would certainly encourage everyone to exercise, to promote brain function and overall health," he said. "But that's not possible for many people, especially those with age-related conditions like heart disease, arthritis, or dementia. For those individuals, there's a particular need for drugs that can mimic the effects of irisin and protect synapses and prevent cognitive decline."

https://www.sciencedaily.com/releases/2019/02/190208173511.htm

Exercise may lessen fall risk for older adults with Alzheimer's

Study indicates exercise may decrease risk of falling for older adults who have Alzheimer's disease and mental health challenges

October 29, 2018

Science Daily/American Geriatrics Society

A research team decided to explore whether exercise could reduce the risk of falling among community-dwelling people with Alzheimer's Disease who also had neuropsychiatric symptoms.

 

Alzheimer's disease (AD) is a brain disease that causes changes that kill brain cells. AD is a type of dementia, which causes memory loss and problems with thinking and making decisions. People with AD and other forms of dementia have difficulties performing the daily activities others might consider routine.

 

Dementia takes a toll on those who live with it -- and it also places a burden on caregivers. Along with problems connected to memory, language, and decision-making, dementia can cause neuropsychiatric symptoms, such as depression, anxiety, changes in mood, increased irritability, and changes in personality and behavior. People who have AD/dementia also have twice the risk for falls compared to people without dementia. About 60 percent of older adults with dementia fall each year.

 

Researchers suggest that having neuropsychiatric symptoms might predict whether an older person with AD/dementia is more likely to have a fall. We also know that exercise can reduce the number of falls in older adults with dementia. However, we don't know very much about how neuropsychiatric symptoms may increase the risk of falls, and we know even less about how exercise may reduce the risk of falls for people with dementia and neuropsychiatric symptoms. A research team decided to explore whether exercise could reduce the risk of falling among community-dwelling people with AD who also had neuropsychiatric symptoms.

 

To learn more, the researchers reviewed a study that investigated the effects of an exercise program for older adults with AD (the FINALEX trial). The study included a range of people living with different stages of AD/dementia and with neuropsychiatric symptoms. Their findings were published in the Journal of the American Geriatrics Society.

 

The original FINALEX study examined and compared older adults who had home- or group-based exercise training with people who didn't exercise but who received regular care. The researchers learned that the people who exercised had a lower risk for falls than those who didn't exercise. There was also a higher risk for falls among those who had lower scores on psychological tests and who didn't exercise.

 

This study revealed that people with AD/dementia and neuropsychiatric symptoms such as depression and anxiety have a higher risk for falls. Exercise can reduce the risk of falling for older adults with these symptoms. Further studies are needed to confirm these results.

https://www.sciencedaily.com/releases/2018/10/181029135235.htm

Move it and use it: Exergaming may help those at risk of Alzheimer's or related dementias

May 15, 2018

Science Daily/Union College

Older adults with mild cognitive impairment (MCI), often a precursor to Alzheimer's, showed significant improvement with certain complex thinking and memory skills after exergaming, according to a new study. The results could encourage seniors, caregivers and health care providers to pursue or prescribe exergames (video games that also require physical exercise) in hopes of slowing the debilitating effects of those with MCI, sometimes a stage between normal brain aging and dementia.

 

The results could encourage seniors, caregivers and health care providers to pursue or prescribe exergames (video games that also require physical exercise) in hopes of slowing the debilitating effects of those with MCI, sometimes a stage between normal brain aging and dementia.

 

"It's promising data," said Cay Anderson-Hanley, associate professor of psychology at Union College and the study's lead author. "Exergaming is one more thing that could be added to the arsenal of tools to fight back against this cruel disease."

 

The study appears in the current issue of Frontiers in Aging Neuroscience.

 

Previously published research by Anderson-Hanley and others found that seniors who exercise using the features of interactive video games experienced greater cognitive health benefits than those who rely on traditional exercise alone.

 

For the latest study, researchers wanted to target older adults diagnosed with or at risk for MCI. MCI is most common in people over age 55. By age 65, approximately 15 to 20 percent of the population shows signs of MCI, according to the Alzheimer's Association.

 

Researchers initially enrolled more than 100 seniors for the study, which was funded through a grant from the National Institute on Aging. Over six months, 14 (evenly split between men and women) persisted with regular exergaming. The average age was 78.

 

The first group of seven was assigned to pedal along a scenic virtual reality bike path several times a week. The second group was given a more challenging task for the brain: pedal while playing a video game that included chasing dragons and collecting coins.

 

The special bikes were placed at a number of sites, including hospitals, community centers and independent living centers.

 

The results were compared against data collected from a separate group of eight seniors who played video games on a laptop but did not pedal, and also a group from the previous research who only rode a traditional stationary bike with no gaming component.

 

At the end of the randomized clinical trial, participants in both the group that pedaled along a virtual bike path and those that chased dragons and collected coins experienced significantly better executive function, which controls, in part, multi-tasking and decision making.

 

"Executive function is like the CEO of the brain. It is key to remaining independent in later life," said Anderson-Hanley. "For example, it allows you to cook two things on the stove at once. It makes sure you don't forget that you are boiling water while also having something in the oven."

 

Benefits for both groups were also seen for verbal memory and physical function, suggesting it may be worth the effort for seniors to incorporate exergaming into a daily exercise regime.

 

Anderson-Hanley acknowledged that further research with a larger sample size is needed to confirm the team's findings. One of the challenges faced was getting older adults in the habit of going to the gym or another venue to exergame. The team is working on a way to have seniors stay home and upload a video game to an iPad that can be used with a stationary bike.

 

In the meantime, the research suggests benefits of exercising while also stimulating the brain with some mental challenge, such as navigating a scenic bike path or interactively playing a video game.

 

"The goal is to explore even more effective ways to prevent or ameliorate cognitive decline in older adults by tailoring accessibility and level of mental engagement in interactive cognitive and physical exercise," she said. "The results suggest that the best outcome for brain health may result when we do both: move it and use it."

https://www.sciencedaily.com/releases/2018/05/180515081728.htm

Exercise may be the best medicine for Alzheimer's disease

July 30, 2013

Science Daily/University of Maryland

Regular, moderate exercise could improve memory and cognitive function in those at risk for Alzheimer's disease in a way no drug can. Scientists studied the effects of exercise on a group of older adults with mild cognitive impairment and found that brain activity associated with memory, measured by neuroimaging, improved after 12 weeks of a moderate exercise program.

 

New research out of the University of Maryland School of Public Health shows that exercise may improve cognitive function in those at risk for Alzheimer's by improving the efficiency of brain activity associated with memory. Memory loss leading to Alzheimer's disease is one of the greatest fears among older Americans. While some memory loss is normal and to be expected as we age, a diagnosis of mild cognitive impairment, or MCI, signals more substantial memory loss and a greater risk for Alzheimer's, for which there currently is no cure.

 

The study, led by Dr. J. Carson Smith, assistant professor in the Department of Kinesiology, provides new hope for those diagnosed with MCI. It is the first to show that an exercise intervention with older adults with mild cognitive impairment (average age 78) improved not only memory recall, but also brain function, as measured by functional neuroimaging (via fMRI). The findings are published in the Journal of Alzheimer's Disease.

 

"We found that after 12 weeks of being on a moderate exercise program, study participants improved their neural efficiency -- basically they were using fewer neural resources to perform the same memory task," says Dr. Smith. "No study has shown that a drug can do what we showed is possible with exercise."

 

Recommended Daily Activity: Good for the Body, Good for the Brain

 

Two groups of physically inactive older adults (ranging from 60-88 years old) were put on a 12-week exercise program that focused on regular treadmill walking and was guided by a personal trainer. Both groups -- one which included adults with MCI and the other with healthy brain function -- improved their cardiovascular fitness by about ten percent at the end of the intervention. More notably, both groups also improved their memory performance and showed enhanced neural efficiency while engaged in memory retrieval tasks.

 

The good news is that these results were achieved with a dose of exercise consistent with the physical activity recommendations for older adults. These guidelines urge moderate intensity exercise (activity that increases your heart rate and makes you sweat, but isn't so strenuous that you can't hold a conversation while doing it) on most days for a weekly total of 150 minutes.

 

Measuring Exercise's Impact on Brain Health and Memory

 

One of the first observable symptoms of Alzheimer's disease is the inability to remember familiar names. Smith and colleagues had study participants identify famous names and measured their brain activation while engaged in correctly recognizing a name -- e.g., Frank Sinatra, or other celebrities well known to adults born in the 1930s and 40s. "The task gives us the ability to see what is going on in the brain when there is a correct memory performance," Smith explains.

 

Tests and imaging were performed both before and after the 12-week exercise intervention. Brain scans taken after the exercise intervention showed a significant decrease in the intensity of brain activation in eleven brain regions while participants correctly identified famous names. The brain regions with improved efficiency corresponded to those involved in the pathology of Alzheimer's disease, including the precuneus region, the temporal lobe, and the parahippocampal gyrus.

 

The exercise intervention was also effective in improving word recall via a "list learning task," i.e., when people were read a list of 15 words and asked to remember and repeat as many words as possible on five consecutive attempts, and again after a distraction of being given another list of words.

 

"People with MCI are on a very sharp decline in their memory function, so being able to improve their recall is a very big step in the right direction," Smith states.

 

The results of Smith's study suggest that exercise may reduce the need for over-activation of the brain to correctly remember something. That is encouraging news for those who are looking for something they can do to help preserve brain function.

 

Dr. Smith has plans for a larger study that would include more participants, including those who are healthy but have a genetic risk for Alzheimer's, and follow them for a longer time period with exercise in comparison to other types of treatments. He and his team hope to learn more about the impact of exercise on brain function and whether it could delay the onset or progression of Alzheimer's disease.

http://www.sciencedaily.com/releases/2013/07/130730123249.htm

 

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