Keeping your brain sharp as you age has a lot to do with your heart — and the younger you start taking better care of it, the better — according to a new scientific statement published Thursday by the American Heart Association.”Dementia is commonly seen as an incurable and relentless disease that cannot be prevented,” said Dr. Fernando Testai, a professor of neurology and rehabilitation at the University of Illinois College of Medicine in Chicago, in a statement.”Evidence shows, however, that adopting a healthy lifestyle and identifying and treating vascular risk factors early may help preserve normal brain function and reduce the burden of Alzheimer’s disease and other related dementias,” said Testai, who chaired the statement writing group.Related video above: Study Confirms Weekly Vigorous Physical Activity Can Reduce Chances of Cognitive DeclineNearly 130 million adults in the United States have some form of heart disease, according to the AHA. Adopting …