The NYT Magazine has a long article on disease and aging though I think the lead family photo is a big misleading (look yourself and contemplate). It doesn't have many surprises in it. It's one of a series of discoveries and reviews that show we age more slowly than we once did, largely because we're sick less often.
The main environmental influences are probably prenatal and certainly before age two (mothers should never smoke), but, there are later effects too. At least for the moment, we are spared much of the disease, parasites, and malnutrition that afflicted our ancestors. As a consequence, we age more slowly.
This is not a surprise to anyone who's studied old family photos. Our ancesters were old at 40 -- rather than 50-55.
FuturePundit, which pointed me to the NYT article, also features a related post about a gene that can be used to tell a person's biological age rather than their chronologic age.
I'm still waiting for the article that shows that aging is non-linear, and that we experience 'bursts' of aging after certain environmental triggers. The old folk tale about 'aging a year in a night' will be shown to be correct.