Nature vs nurture: what can be learned from the oldest-old's claims about longevity?

Beneficial genetic or environmental factors that influence the length and quality of life can be evaluated while studying supercentenarians. The oldest-old can withstand serious/fatal illnesses more than their peers and/or their ageing rate is decreased. Supercentenarians are an interesting group of individuals whose lifestyle is not particularly healthy according to the common guidelines; namely, some of them seem to have similar harmful behaviours, but still manage to stay healthier for longer and, while eventually dying from the same degenerative diseases as the general population, they develop symptoms 20 to 30 years later. As there are not many supercentenarians by definition, it is worthwhile to diligently collect their data to enable future meta-analyses on larger samples. Namely, much can be learned from supercentenarians' habits and lifestyle choices about the ageing process. Contributions of genetics, lifestyle choices and epigenetics to their extended life span are discussed here.