I love the blog at the British Medical Journal, and I have a been a subscriber for some time. Typical of its great stuff are the following two summaries from the current NEJM:
The trouble with medical research is that it involves so much boring hard work. First carry out 2,446,431 person-years of follow-up involving questionnaires on aspirin use every two years. Having picked up 636 incident colorectal cancers, get all the paraffin-embedded histology specimens of these cancers and test them for the expression of cyclo-oxygenase-2 activity. Then analyse the data to determine the preventive effect of aspirin on colon cancers with and without COX-2 expression. You write up and rewrite the thing for the New England Journal and, hey, with luck you may be able to move yourself and your family to another ill-paid but more prestigious job in a distant university. Thank God there are people willing to do it.
By the time we turn 45, Evolution has largely lost interest in us, despite all the arguments about survival advantage from the extended family, altruism, and so forth. The human urinary tract is a good example. The Universe cares little whether older women leak when they cough, or older men get big prostates.
The second point is an interesting one. Will widespread longer life spans eventually mean that evolution ceases turning a blind eye to people over 45? One might think so, but then again, most of those people are past the point where they are propagating the species, so it remains more likely that evolution will continue to not favor middle-aged sorts.