Study of world's oldest person reveals biological age 23 years younger than her actual age

A study of María Branyas Morera, the world's oldest person who died at 117, found her biological age was roughly 23 years younger than her chronological age, based on epigenetic clocks and other molecular analyses. The findings were published in a 2025 study in Cell Reports Medicine. Researchers analyzed her genome, blood, saliva, and stool samples collected when she was 116. They found extremely short telomeres and age-related immune changes, but also a youthful gut microbiome, low inflammation, efficient lipid metabolism, and rare genetic variants linked to longevity and disease protection. Branyas, who lived through two world wars, the 1918 flu pandemic, the Spanish Civil War, and COVID-19, never smoked or drank alcohol and followed a Mediterranean diet with regular yogurt consumption. Her longevity is attributed to a combination of genetic resilience and favorable lifestyle factors.