Reaching the age of 100 was once considered almost mythical, the kind of milestone reserved for family legends or grainy black-and-white photographs of smiling great-grandparents who seemed to have outlived entire eras. For most of human history, simply surviving childhood diseases, food shortages, or infections was an accomplishment, and life expectancy rarely stretched far beyond the sixties. Public health breakthroughs—clean water systems, modern sanitation, vaccines, antibiotics, advanced diagnostics, and preventative medicine—gradually rewrote that story.
Today, living into one’s eighties or nineties is no longer extraordinary in many developed countries, and centenarians are steadily becoming more visible. Yet even with these advances, crossing the 100-year mark remains statistically rare enough to spark fascination. Why do some people reach triple digits with surprising vitality while others face serious illness decades earlier? Scientists have chased answers through every conceivable lens: diet quality, cardiovascular fitness, stress exposure, sleep patterns, socioeconomic stability, education levels, environmental toxins, and access to healthcare. Amid all those variables, researchers have begun paying closer attention to something far simpler and completely unchangeable: blood type.
It’s a biological trait assigned at birth, something most people barely think about unless they’re donating blood or filling out medical paperwork. But emerging research suggests that this quiet genetic signature—along with subtle, long-term health markers circulating in the bloodstream—may hold clues about why certain bodies age more gracefully than others. What once sounded like folklore or luck is increasingly being explored through data science, epidemiology, and precision medicine, turning longevity from mystery into measurable probability. It may simply be about stacking small, sustainable advantages year after year until, almost quietly, those years add up to a lifetime far longer than anyone once imagined.