An interesting study was published in Health Affairs last year finding a fairly stark difference in life expectancy based on years of education (emphasis added).
In this article we update estimates of the impact of race and education on past and present life expectancy, examine trends in disparities from 1990 through 2008, and place observed disparities in the context of a rapidly aging society that is emerging at a time of optimism about the next revolution in longevity. We found that in 2008 US adult men and women with fewer than twelve years of education had life expectancies not much better than those of all adults in the 1950s and 1960s. When race and education are combined, the disparity is even more striking. In 2008 white US men and women with 16 years or more of schooling had life expectancies far greater than black Americans with fewer than 12 years of education—14.2 years more for white men than black men, and 10.3 years more for white women than black women. These gaps have widened over time and have led to at least two “Americas,” if not multiple others, in terms of life expectancy, demarcated by level of education and racial-group membership.
The actual study is behind a stupid paywall, but there doesn’t seem to be any consensus as to what is causing such a large gap. Part of it appears to be down to things like increased smoking rates among people with less education (especially white women) as well as more obvious things like higher levels of education begin correlated with better access to health care.