Older adults who remain cognitively sharp as they age have a genetic advantage over their peers, new research shows. Scientists at the University of Illinois College of Medicine Chicago found that so-called super-agers generate twice as many new neurons in the hippocampus — a part of the brain critical to learning and memory — as typical older adults. Their research was published Wednesday in the journal Nature . “This discovery means that the super-agers have a molecular capability that allows them to have higher [cognitive] performance, and that includes more neurogenesis,” said Orly Lazarov, the director of UIC’s Alzheimer’s Disease and Related Dementia Training Program , who led the research.…