In 1909 we didn't have antibiotics and but a few vaccines. Those two factors alone shortened the overall lifespan. For example when Social Security was enacted the Govt. chose 65 as the retirement age, due to the fact if you made it that far, you didn't have much longer to go, 3-5 years generally. With the advent of antibiotics, the refinement of vaccines, and chemical fertilizers during and after WWII, populations and life expectancies soared.
The longer you live the more likely you are be hit with a cancer of some type, about 1 in 3 Americans will die from it. Is the high skin cancer rate from dietary fats or the higher percentage of ancient coots heading to sunny locations for two decades of retirement after spending their working years indoors?