Jim wrote:

> Are increased health and increased life expectancy
> necessarily the same thing?  

Life expectancy is not the same thing as health, though they are closely
related. Life expectancy is affected by non-health factors like wars and
wild predators. And of course it's to possible to live a long but unhealthy
life.

> To what extent is medicine
> keeping us alive despite our poor health?

According to the table at the link below, life expectancy in the US was only
47.3 years in 1900. A hundred years later, in 2000, it was 76.9. That is a
huge increase in only 100 years. Surely the discovery of penicillin and
other medical advances are major reasons for the increase in longevity. 

http://www.cdc.gov/nchs/data/hus/tables/2002/02hus028.pdf

-gts