People probably did not live long enough to show it. the average life span in Rome was 21 years of age. I found that on several web pages. 21 years average!
Average probably isn’t the best thing to look at, given high infant mortality.
Here’s an interesting study that looks at popes and artists living in the Vatican. It’s identifying the median age a cardinal becomes pope and how many years he lives after that. Much longer.
https://academic.oup.com/ije/article/34/6/1435/707557
Longevity of popes and artists between the 13th and the 19th century