February 08, 2018
By Kristi Birch
Researchers at the University of Kansas Alzheimer's Disease Center have launched the largest, most comprehensive study ever on the role exercise plays in brain health and cognitive decline in older people.
"This study is important because there is still doubt about exercise affecting the brain," said Jeffrey Burns, M.D., MS, co-director of KU Alzheimer's Disease Center and a co-principal investigator on the study. "The problem is that there is no definitive proof yet. We want to put that to rest."
Organizers plan to enroll 640 participants between the ages of 65 and 80 with underactive or sedentary lifestyles and normal brain function into a 5-year, $21.8 million study funded by a grant from the National Institute on Aging, part of the National Institutes of Health. Researchers at the KU Alzheimer's Disease Center are teaming up with scientists from the University of Pittsburgh and Northeastern University to conduct the study known as IGNITE: Investigating Gains in Neurocognition in an Intervention Trial of Exercise.
An estimated 5.5 million Americans have Alzheimer's disease, and this number could rise to 16 million by 2050, according to the Alzheimer's Association.
Since drug treatments to slow or prevent dementia have been largely unsuccessful thus far, exercise is another possible hope for people with dementia or Alzheimer's. IGNITE researchers would like to be able to answer once and for all whether moderate aerobic exercise such as brisk walking or bicycling can improve brain health in older adults, slow cognitive decline and potentially delay the onset of Alzheimer's disease.
IGNITE participants will be randomly assigned into one of three groups: one group will do only stretching and toning exercises, with no regular aerobic activity; another group will be required to do 150 minutes per week of aerobic exercise, the amount currently recommended by Department of Health and Human Services to stay healthy; and the last group will do 225 minutes a week of aerobic exercise.
Before starting the one-year trial, participants will undergo a thorough assessment that they will repeat again at the end, so researchers can compare the results. The assessments include MRIs to look at brain structure; functional imaging, to show which parts of the brain are engaged during cognitive tasks; pulse wave velocity tests to monitor blood flow; cognitive testing through pen and paper tests; hair sampling to measure cortisol levels; PET scans to measure the build-up of the amyloid protein, which is ubiquitous in patients with Alzheimer's disease; and cardiorespiratory fitness testing.
Participants will receive a free one-year membership to the YMCA where three times a week they will be asked to walk on a treadmill, pedal a stationary bicycle or use an elliptical machine for the number of minutes assigned to their respective group. A trainer will be assigned to each person to monitor their attendance and record their heartrates. Any additional exercise will need to be recorded in the participant's activity journal.
"We expect to find that exercise positively impacts the brain in the form of improvements in memory and cognition and healthy changes in the brain's structure," said Burns.
Previous research on the role of exercise and brain health has proved inconclusive, largely because of inconsistency among how the studies were conducted. For example, some studies had fewer than 50 participants, while others did not ensure that participants consistently stuck to the prescribed exercise regimen or closely monitor the exercise intensity.
Organizers of the IGNITE study, conducted by three of the leading universities in the field of exercise and brain health, plan to address many of those issues. IGNITE will be the first with a sample size this large that includes MRI brain imaging.
If the researchers' hypothesis proves correct, then exercise could be regarded as important to brain health as it is to heart health. "If we could prove that exercise provides the same benefits to brain health as it does to cardiovascular health, then we can really make a difference," said Burns.