The secret of eternal youth, we all want to know. Or well, eternal youth, let’s start with how it is possible that some people easily reach 100. According to new research, this has to do with the excellent immune system of the old people.
We have about 30 trillion cells in our body and our health depends on how well they interact and support each other. The immune system plays a crucial role in this. As we get older, this system slowly starts to work less well. But people over 100 are lucky: they are probably less susceptible to age-related diseases, because their immune system continues to function well into old age.
Special immune system
Researchers from, among others, the American Boston University have now discovered what makes that immune system of these very old people so special. It turns out that they have a different composition and level of activity in their immune cells and that they have a highly functioning immune system that has successfully adapted to a variety of age-related diseases, enabling them to live exceptionally long lives. These immune cells may help activate important mechanisms to recover from disease.
Better recovery from illness
“Our data support the hypothesis that people over 100 have protective immune factors that allow them to better recover from disease and reach an extremely old age,” said lead researcher Tanya Karagiannis of the study. Tufts Medical Center out.
“We have collected and analyzed the largest dataset of cells from over 100s known to date, allowing us to identify the unique characteristics of this population. They do indeed have molecular and lifestyle factors that contribute to their longevity,” explains another researcher, Stefano Monti.
To identify the immune-specific patterns of aging and extreme longevity, the scientists applied single cell sequencing on peripheral blood mononuclear cells (PBMCs), such as the well-known T cells, from seven over-100s participating in the New England Centenarian Study, one of the largest studies ever on the longevity of people who live past 100.
Escaping Aging
The researchers integrated this dataset with two public RNA-sequencing datasets from PBMCs to trace changes in immune cell composition and transcription over a lifetime and at extreme old age. Finally, using modern computer techniques, they investigated how cell type composition (the proportion of different cell types) and activity changed with age and whether people over 100 had specific immune cells that helped them escape normal aging.
Their analysis confirms observations from previous aging studies and identifies new cell-type specific changes in immune cell composition and transcription that are unique to the over-100s.
Self-learning immune system
When people contract an infection and recover from it, the immune system learns to adapt, but this ability diminishes as we age. “The immune profile we observed in the over 100s confirms a long history of exposure to infections and the ability to recover from them. It also supports the hypothesis that people over 100 have extra protective factors that give them a better ability to recover from infections than others,” says researcher Paola Sebastiani of the Tufts Medical Center.
Foundation for healthier living
According to the researchers, their findings lay the foundation for research into the mechanisms behind the strong resistance of extremely old people, which contributes to longevity. “Over-100s and their exceptionally long lives provide a blueprint for how we can lead more productive and healthier lives. We want to learn everything we can about resistance to disease and extending healthy lifespans,” said researcher George Murphy.
How exactly you get to 100, that question has not yet been answered. It does seem clear that you have to be at least a little lucky with your immune system.