Long-Lived Hispanics!
Eugene Volokh at the Volokh Conspiracy blog pulls together a fascinating set of links and observations regarding an obscure but interesting (at least I never heard it–feel free to upbraid me for behind-the-times ignorance) demographic fact: that in America, "foreign-born Mexican and Other Hispanic adult[s]…experienc[e] mortality rates that are 35% to 47% lower than those experienced by non-Hispanic whites…these differences translate into approximately five to eight years of additional life expectancy at age 45." Apparently, there's no settled theory explaining this that's totally convincing–though these results may also be merely "due to data problems and differing methodologies." Following all the links and arguments in the post provides a demo-fabulous time for all.