Exercise Wards off Some Effects of Alzheimer's Disease
New research highlights the positive influence of an active lifestyle on brain health.
--by Alexia Severson
We all know exercise is good for our bodies, but new research shows that an active lifestyle can also give our brains a boost and ward off the effects of Alzheimer’s Disease (AD).
According to World Health Organization, more than 35 million people live with AD worldwide, and the prevalence of this devastating disease is expected to double by 2030. It is the most common cause of dementia and, for now, there is no cure.
The Expert Take
In this study, presented at the annual meeting of the Radiological Society of North America, Cyrus Raji, Ph.D., radiology resident at the University of California, researched the role of an active lifestyle on brain structure in patients with normal cognition and AD. Lifestyle factors he examined included: recreational sports, gardening and yard work, bicycling, dancing, and riding an exercise cycle.
Researchers used these factors, along with advanced magnetic resonance imaging (MRI) techniques to help them understand the connection between an active lifestyle and gray matter volume, a key marker of brain health.
“Larger gray matter volume means a healthier brain. Shrinking volume is seen in Alzheimer's disease," Raji said.
During their research, the team found a strong association between energy output and gray matter volumes in areas of the brain crucial for cognitive function. For example, greater caloric expenditure was related to larger gray matter volumes in the frontal, temporal, and parietal lobes, including the hippocampus, posterior cingulate, and basal ganglia. They also found a link between high energy output and greater gray matter volume in patients with mild cognitive impairment and AD.
According to Raji, gray matter is made up of neurons that facilitate cognition and higher order cognitive processes. The areas of the brain that benefit from an active lifestyle are the ones that consume the most energy and are most sensitive to damage.
"What struck me most about the study results is that it is not one, but a combination of lifestyle choices and activities that benefit the brain," Raji said.
The positive influence of an active lifestyle on the brain may be due to improved vascular health, Raji said.
Source and Method
Researchers examined how an active lifestyle influenced brain structure in 876 adults, with an average age of 78, drawn from the multi-site Cardiovascular Health Study. The patients' mental conditions ranged from normal cognition to Alzheimer's disease.
MRI scanning and a technique called voxel-based morphometry, an advanced method that allows a computer to analyze an MRI image, were used to model the relationships between energy output and gray matter volume. Researchers controlled for age, head size, cognitive impairment, gender, body mass index, education, study site location, and white matter disease.
This research not only gives patients yet another reason to stay active, it also helps us to better understand the relationship between our bodies and our brains. The more we know about AD and ways in which it can be alleviated, the better doctors are able to treat patients with AD and the closer we are to finding a cure.
In a study published in The Lancet Neurology in 2005, researchers investigated the association between leisure-time physical activity at midlife and the development of AD. They found that leisure-time physical activity at midlife decreases the risk of AD later in life, and also delays the onset of AD in genetically susceptible individuals.
Another study, published in the American Journal of Epidemiology in 2002, focused on the association between social interaction and the risk of developing AD. Researchers in this study found that “stimulating activity, either mentally or socially oriented, may protect against dementia, indicating that both social interaction and intellectual stimulation may be relevant to preserving mental functioning in the elderly.”
A study published in the Journal of Neuroscience in 2005 also concluded that exercise may work as a simple intervention during the onset or progression of AD.