Hi, thanks for the replies everyone. I find it very interesting.
I also support the 'longevity' genes. I just found my great-grandmother had the following siblings:
Luite (1884-1986)
Marrigje (1888-1981)
Jentje (1896-1996)
so a fairly long lived family. My own longest lived ancestor (doesn't beat some already here!) was Ann Usher, who died in 1871 aged 101.