American Heart Association President, Mitchell S. V. Elkind, M.D., M.S., FAHA, FAAN, professor of neurology and epidemiology at Columbia University Vagelos College of Physicians and Surgeons and attending neurologist at NewYork-Presbyterian/Columbia University Irving Medical Center in New York, New York offers perspective via Zoom on EPI Lifestyle 2021 presentations P149, MP24 and MP67. copyright American Heart Association "We've known for some time that physical activity is an important component of heart health, and the Heart Association has recommended that people engage in at least 150 minutes per week of moderate intensity physical activity or 75 minutes a week of even more vigorous activity for their heart, but what's been less clear is what the effect of physical activity is on brain health, and also what is the effect of not just physical activity but of avoiding sedentary behavior as opposed to engaging in active exercise? Now, three analyses being presented at the EPI/Lifestyle meeting provide evidence that sedentary behavior, apart from physical activity, is associated with unhealthy brain aging. Two of these analyses come from the Atherosclerosis Risk in Communities study, or ARIC, and they looked at people who'd been followed for many years and who completed questionnaires that described their levels of physical activity, as well as time spent watching TV, which they considered a proxy for the amount of sedentary behavior, and one of the studies looked at cognitive decline and dementia, and the other looked at the effects on brain structure using MRIs that the participants had undergone during the course of their participation in the study, and then the third study or analysis looked at people who were enrolled in the CARDIA study, which includes a younger population of people, and in general, the investigators across these different analyses involving two different epidemiological studies found that people who engaged in more TV watching, more time spent in sedentary behavior, were more likely to experience cognitive decline and to have structural brain differences than people who spent less time in physical activity. So in ARIC, the effects were present for cognitive decline but, interestingly, not for a diagnosis of dementia itself, and also in the ARIC study, the effects were present for the gray matter deep within the brain, whereas in the CARDIA study they found effects for the brain matter in the cortex or the surface of the brain, so subtle differences there. Now, what's also interesting is that these results did not depend on how much physical activity the participants engaged in, suggesting that sedentary behavior has an effect apart from that of physical activities. So avoiding sitting still has a separate effect from engaging in exercise at other times in one's life and activities."