Life expectancy is actually a backward looking number. Eg: life expectancy of 78 years is only relevant for people born ~78 years ago. For people born after that, it's unknown.
And looking at the health of the middle age people today, I say life expectancy for most people is about to plunge into the 50s. It'll be a rude awakening.
The real problem is we are at the stone ages when it comes to medicine. The problem is worsen by the fact that treatment is more profitable than cure. In fact, cure eliminates income all together.