New Study: Active Lifestyle Preserves Brain Structure, May Slow Alzheimer’s Disease
Gray matter increased in brain areas crucial for cognitive function (Nov. 26)
An active lifestyle helps preserve gray matter in the brains of older adults and could reduce the burden of dementia and Alzheimer's disease (AD), according to a new study presented at the annual meeting of the Radiological Society of North America (RSNA).
More than 35 million people worldwide have dementia, according to the World Health Organization (WHO), and the prevalence is expected to double by 2030. AD is the most common cause of dementia and currently has no cure.
Cyrus Raji, MD, PhD, and colleagues at the University of California—Los Angeles examined how an active lifestyle can influence brain structure in 876 adults (average age: 78 years) drawn from the Cardiovascular Health Study. The patients' conditions ranged from normal cognition to AD.
The lifestyle factors examined in the study included recreational sports, gardening, yard work, bicycling, dancing, and riding an exercise cycle.
The researchers used magnetic resonance imaging (MRI) and a technique called voxel-based morphometry to model the relationships between energy output and the volume of gray matter in the brain.
“Voxel-based morphometry is an advanced method that allows a computer to analyze an MR image and build a mathematical model that helps us to understand the relationship between active lifestyle and gray matter volume,” Dr. Raji said. “Gray matter volume is a key marker of brain health. Larger gray matter volume means a healthier brain. Shrinking volume is seen in Alzheimer's disease.”
After controlling for age, head size, cognitive impairment, gender, body mass index, education, location of the study site, and white matter disease, the researchers found a strong association between energy output and gray matter volumes in areas of the brain crucial for cognitive function. Greater caloric expenditure was related to larger gray matter volumes in the frontal, temporal, and parietal lobes, including the hippocampus, posterior cingulated ganglia, and basal ganglia. A strong association was observed between high energy output and greater gray matter volume in patients with mild cognitive impairment and AD.
“Gray matter includes neurons that function in cognition and higher-order cognitive processes,” Dr. Raji said. “The areas of the brain that benefited from an active lifestyle are the ones that consume the most energy and are very sensitive to damage.”
Dr. Raji remarked that the positive influence of an active lifestyle on the brain was likely due to improved vascular health.
“Virtually all of the physical activities examined in this study are some variation of aerobic physical activity, which we know from other work can improve cerebral blood flow and strengthen neuronal connections,” he said.
Source: RSNA; November 26, 2012.