Scientists believe that the immune system of elderly people is specially adapted to longevity.
They explained that the immune system of these individuals renews and recycles its cells at a rate similar to that of people decades younger, which helps prevent the accumulation of damaged proteins and dangerous mutations that can lead to heart disease, cancer, and dementia.
The researchers also observed a distinctive feature in the behavior of CD4+ helper T cells , which coordinate the immune response. In centenarians, these cells behave like cytotoxic T cells, which normally attack infected or abnormal cells. This pattern is rare in younger individuals.
An analysis of data from an ongoing study involving more than 140 centenarians and 20 supercentenarians, including Sister Ina Cannabarro Lucas , who was the world's oldest living person and died at the age of 116 years and 326 days in the spring of 2025, showed that most participants retained full mental faculties and were able to perform their daily tasks independently, despite limited or no access to modern medical care.
Peter Sramek , executive director of the Healthy Longevity Clinic, pointed out that a range of factors likely contribute to reaching the age of 100 and above, most notably so-called longevity genes , which are genes that are not widely distributed.
Sramk said, "These factors may only be present in 2% of the population. These people don't necessarily need to follow a perfect lifestyle."
He added, "They may have bad habits, they may not exercise, but they still live long and healthy lives. These are exceptional cases."
