Hope for a fountain of youth may spring eternal, but these days it is surprisingly active among the ranks of highly educated and even scientifically trained professionals — despite what experts say is a lack of compelling clinical evidence for any particular treatment.

Resveratrol, which has protected lab animals from heart disease, cancer, Alzheimer’s and Parkinson’s diseases, seized the public imagination in November when two prominent studies showed that mice taking the compound lived longer and ran farther than mice not taking it. Still, scientists say it’s far from certain that it will extend human life.