"Almost an urban myth"
http://www.boeing.com/companyoffices...nars/Rumor.pdf
Work on Shell retirees showed that retirees at 55 died earlier than those at 65 (presumably because some of the early retirees did so because of poor health)
http://www.bmj.com/cgi/rapidpdf/bmj....48704.E0v1.pdf
But note both the above do not address night shift issues, which from the BBC article, seems to increase breast cancer rates.