What does this mean though? Ancient lifespans were actually quite close to modern American lifespans. They likely had higher childbirth mortalities so the average may have been low but the modal lifespan was around 70 years[0] which is right around in line with the modern American. Lifespans were significantly shorter in medieval Europe but that was probably the lowest it's ever gotten and that was a relatively short period in human (or at least Western) history. Yet we still find fossil evidence that early hominins and early humans generally had great dental health.[1] Even the Romans, peasant and nobility included, did.[2]

[0] https://theconversation.com/hunter-gatherers-live-nearly-as-...

[1] https://www.npr.org/sections/health-shots/2013/02/24/1726888...

[2] https://www.docseducation.com/blog/ancient-romans-had-health...