Man has been slowly expanding his lifespan. Historically, the oldest person ever lived to 122. It is possible that some lived longer than that without being part of recorded history,but statistics don't make it likely.
Statistics are tricky on this one. Life expectancy at birth was very short in ancient times, but those that did live past infancy and childhood could have lived to grow old. So it seems that some have virtually always managed to live past 70, but now many more do so and many of them live into their 80's and 90's.
As far as the Bible goes, the same book that says people lived nearly 900 years says that man started out only a bit over 6000 years ago and that a global flood happened some 4300 years ago, give or take, and wiped out all animal and human life except for a tiny gene pool.
And don't forget that the story forgot that dinosaurs existed. That's evidence enough for me that the writings were based on what people believed at the time of writing and that no supernatural power helped them with the story.