> No. I would guess the biggest factor is our number one killer, heart disease. Healthy lifespan.... People live a long time with heart disease, but they are never healthy again. Same with many terminal cancers, etc.

Those are the leading causes of death, but not the leading causes of the recent decline in life expectancy (heart disease has not contributed to a dramatic decrease is life expectancy).

The recent decrease is due to deaths from drug overdoses. They aren't the leading cause of death, but they have caused the life expectancy to decrease in the last few years.