IMO most of 'average life expectancy' can be attributed to human ignorance and savagery. Like the savagery of pouring dyes into rivers until too many people die of bladder cancer, then moving the factories to another continent. Repeatedly. Or the savagery of using scientific knowledge to create nukes ... and use them.

One example of ignorance is knee-jerk, gainsaying, scientism about alternatives to Western medicine. My use of Neti was recommended by a well-trained physician, and it was very beneficial. There was indeed practical wisdom in the world before the rise of materialist rationalism.

Oh yeah... and western medicine couldn't save the lady's ass. I'm sure the bill was VERY healthy though.