But for most the news that formal education early in life might help delay some of the symptoms of dementia comes decades too late. "People past their education age seemed to be disappointed by the results," Keage says. She emphasizes, however, that education seems to be "just one more factor that can modify your dementia risk." Doraiswamy says it likely plays a small role and is probably less important than genetics as well as a host of health and lifestyle factors that are only starting to be parsed out.
"There's probably still some neuroplasticity left in the brain during adulthood," Doraiswamy notes. He suggests more studies of the impact of midlife and late-life hobbies and occupations to see what patterns education duration plays throughout life—and what those long past their campus days can do to improve their odds.
For now, research suggests a healthy diet, exercise and social engagement as likely to help stave off the dreaded condition. So if you did not go in for a PhD, Keage says, "I don't think it's time to give up yet."