After controlling for age, head size, cognitive impairment, gender, body mass index, education, study site location 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 cingulate and basal ganglia. There was a strong association 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." A key aspect of the study was its focus on having variety in lifestyle choices, Dr. 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. Dr. Raji said 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. "Additional work needs to be done," Dr. Raji added. "However, our initial results show that brain aging can be alleviated through an active lifestyle." Coauthors are H. Michael Gach, Ph.D., Owen Carmichael, Ph.D., James T. Becker, Ph.D., Oscar Lopez, M.D., Paul Thompson, Ph.D., William Longstreth, M.D., Lewis Kuller, M.D., and Kirk Ericson, Ph.D. Note: Copies of RSNA 2012 news releases and electronic images will be available online at RSNA.org/press12 beginning Monday, Nov. 26. RSNA is an association of more than 50,000 radiologists, radiation oncologists, medical physicists and related scientists, promoting excellence in patient care and health care delivery through education, research and technologic innovation. The Society is based in Oak Brook, Ill. ( RSNA.org) Editor's note: The data in these releases may differ from those in the published abstract and those actually presented at the meeting, as researchers continue to update their data right up until the meeting. To ensure you are using the most up-to-date information, please call the RSNA Newsroom at 1-312-949-3233.