A new study reveals that an active lifestyle helps conserve gray matter in the brains of older adults and may lessen symptoms of dementia and Alzheimer’s disease (AD).
Researchers wanted to investigate how an active lifestyle might affect brain structure in 876 adults (average age 78 years) whose mental states ranged from normal cognition to Alzheimer’s dementia.
“We had 20 years of clinical data on this group, including body mass index and lifestyle habits,” said Cyrus Raji, M.D., Ph.D., radiology resident at the University of California in Los Angeles.
“We drew our patients from four sites across the country, and we were able to assess energy output in the form of kilocalories per week.”
The lifestyle factors taken into account included recreational sports, gardening and yard work, bicycling, dancing and riding an exercise bike.
The researchers used magnetic resonance imaging (MRI) and a technique called voxel-based morphometry to model the relationships between energy output and gray matter volume.
“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,” 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, study site location and white matter disease, the researchers found a significant link between energy output and gray matter volumes in areas of the brain necessary for cognitive function.
Greater caloric output was associated with larger gray matter volumes in the frontal, temporal and parietal lobes, including the hippocampus, posterior cingulate and basal ganglia. There was a significant link between high energy expenditure and greater gray matter volume in patients with mild cognitive problems and AD.
“Gray matter includes neurons that function in cognition and higher order cognitive processes,” 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.”
A key feature of the study was its focus on having variety in lifestyle choices, Raji noted.
“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,” he said.
Raji said the positive effect of an active lifestyle on the brain was likely due to better 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.
“Additional work needs to be done,” Raji added. “However, our initial results show that brain aging can be alleviated through an active lifestyle.”