Common missconception: people didn't just die in their thirties, the average is brought down somewhat hard by lots of infant death, childbirth complications and the like.
@Prunebutt says it right, it's the advancements in medicine, but thats more reactively treating diseases than proactively lengthening the lifespan.
Wasn't there also something that Obama almost exclusively golfed at Andrews Base, a secure location near D.C. while the other guy had to go to his own club where the Secret Service had to book rooms in Trumps own hotel?