Healthy oldest-old rather than centenarians or healthy centenarians have been chosen for this study based on demographic data, which suggests that in western countries less than 36% of individuals live up to 85 years and that only one third of these will do so in good health (∼12% overall) [45]. Hence, healthy oldest-old are uncommon in the population, but not as rare as centenarians (1 per 3300 people in the US). We have collected lifestyle, education and other information for the entire collection of healthy oldest-old (550 individuals, of which the 47 individuals sequenced are a subset) and also for 550 controls for use in future association study, to be able to control for major lifestyle and socio-economic factors in future association studies.
