The researchers point out that Brazil is an important, yet little-used source for the study of extreme longevity. The population of Brazil is highly diverse and contains millions of genetic variants that are missing from common genetic databases. Among these variants, there are also rare changes associated with stronger immunity and better "maintenance" of cells. Brazilians over 110 often remain in good mental health. They often survive even serious infections. They come from families in which several members live to be over 100 years old. These observations show aging as a manifestation of biological resilience, not just gradual decline.