If you have a mathematical or science background this post is fascinating: Your Body Wasn’t Built to Last.
Of course theology got there a long time ago:
Then the LORD said, “My Spirit shall not abide in man forever, for he is flesh: his days shall be 120 years.” (Gen 6:3 ESV)
The years of our life are seventy, or even by reason of strength eighty (Psa 90:10 ESV)
But we have this treasure in jars of clay, to show that the surpassing power belongs to God and not to us. (2Co 4:7 ESV)