The brain is arguably the most important organ in the body; it can't be replaced. And there are several steps one can take to ensure the brain stays healthy. For example, Ausim Azizi, chair of neurology at Temple's medical school, says exercise can help. "Research shows that aerobic exercise increases the generation of new cells in the memory areas of the brain," he said, adding that a brain boost can come from as little as 15 minutes of exercise, three times a week.