A study says that supercentenarians have stronger immune systems. A geriatrician explained why
Supercentenarians, who are also the best at defending themselves
Supercentenarians also have superpowers against disease. This is suggested by a study published in the journal Cell Reports, conducted by Osaka University. The study investigated the immune systems of 28 seniors over 70, including 10 aged 110 or older, and found that the older they get, the stronger they become.
How the immune system of supercentenarians works
Specifically, they investigated the presence of CD4 cytotoxic T lymphocytes, nicknamed "killer immune cells": these are antibodies that not only repel attacks from viruses, bacteria, and tumor cells, but actually destroy them. They discovered that among the age groups into which they divided the participants—70-99, 100-109, and 110 and older—the centenarians not only had the most CD4 cytotoxic T lymphocytes, but also had receptors that matched those found on the immune cells of cancer patients, despite never having had cancer. In short, it was as if they were more capable of actively defending themselves despite their advanced age and the fact that they had never been ill. "Rather than showing signs of exhaustion, these cells remain highly active and could help the body cope with persistent threats that increase with age," commented the study's first author, Kosuke Hashimoto, emphasizing that discoveries like these could also be very useful in the oncology field.
Why older people have stronger immune systems
How is it possible for an elderly person to have a stronger immune system? "This phenomenon was already partially known," says Dr. Stefano Crooke, a geriatrician at the Villalba Private Clinic in Bologna. "Studies similar to this one, conducted through autopsies on centenarians, many due to old age and not disease, have discovered, for example, that in many cases they had small, scattered, but encapsulated tumors. It was as if their immune system had caged the cancer, protecting them."
"Lymphocytes are a type of white blood cell that play a crucial role in the immune system, defending us from viruses, bacteria, and tumor cells," Crooke continues. "Although they don't intervene, some of these lymphocytes—the CD4 CTLs cited in the study—retain memory of the attack they've suffered, ready to intervene if necessary to eliminate the threat." The good news is that their multiplication and presence are closely linked to lifestyle: following a healthy diet, exercising, and leading a socially active life are all beneficial to our immune system, and therefore to our health and happiness.
How to strengthen the immune system
"It's a mechanism closely linked to what in medicine is called psychoneuroendocrinoimmunology (PNEI)," continues Dr. Crooke, introducing the science that studies the connections between the mind and the nervous, endocrine, and immune systems. The basic mechanism is simple: just think of cortisol, the stress hormone that, if produced in excess, weakens the immune system. "A stressed individual produces more cortisol, and this creates chronic, low-grade inflammation that underlies aging. On the other hand, a healthy individual who eats properly and leads an active lifestyle isn't subject to these hormonal changes, partly because they produce more endorphins, which are the neurotransmitters that inhibit the production of cortisol, thus strengthening the immune system," concludes the doctor. In short, this is why it's said that resilience is a key to longevity.