Centenarians were once those people whose birthdays became community events or even newspaper features. Even today, hitting a century of life is rare, and scientists have long wondered why some people live far longer than others. Is it luck? Genetics? Lifestyle? Or a combination of all three?
A study from Sweden gives us a glimpse into the answer. Researchers had access to decades of health records for tens of thousands of people, and they wanted to know whether routine blood tests taken in midlife could reveal who might eventually make it to 100.
Decades of Tracking
The study looked at 44,637 people from Stockholm County. These participants, all born between 1893 and 1920 (ages 64 to 99), had routine blood tests performed between 1985 and 1996. After that, the researchers followed these individuals for up to 35 years, tracking disease, death, and residency through national registers.
Out of all these participants, 1,224 reached the age of 100, and most of them, around 85 percent, were women. This didn’t come as a surprise as women generally live longer than men. But the researchers weren’t just counting birthdays. They also wanted to know if blood markers measured decades earlier could reveal something deeper about their longevity.
