Weakness and sickness are associated with old age. Scientists are working to change that, confronting one of the most difficult difficulties humans face with "cellular senescence," a little-known but growing subject in the study of aging.
It is based on the idea that cells eventually stop dividing and enter a "senescent" condition. Although the body kills the majority of them, others live on as zombies. They don't die, but they can atrophy surrounding cells, exactly like when a bowl includes multiple fruits and one decaying one spoils another, according to Nathan Labraser of the Mayo Clinic.
These "zombie cells" amass in the bodies of the aged, and there is mounting evidence that they are linked to issues such as dementia, cardiovascular disease, and osteoporosis.
Scientists are wondering if there are any techniques to prevent the growth of zombie cells.
According to LeBrasseur, "understanding aging — and intervening in the biology of aging — is perhaps the best opportunity it has of improving human health."
The number of people over the age of 65 is predicted to double globally by 2050, according to Viviana Pérez Montes of the National Institutes of Health, therefore cellular senescence is "very much in trend."
Hundreds of companies and academic groups are researching medications that target senescent cells. And there are hints that people can contribute to this endeavor by employing Soler's strategy: exercise.
While no one claims that aging assures a longer life, Tufts University researcher Christopher Wiley believes that in the future, much fewer people will suffer from diseases connected with aging.
“I’m not looking for the fountain of youth,” said Wiley. “I’m looking for a source that can stop me from getting sick as I get older.”
Leonard Hayflick, the scientist who discovered cellular senescence in 1960, is also significant at the age of 94. He teaches anatomy at the University of California, San Francisco, and continues to write, present and speak on the subject.
He accidentally discovered senescence while cultivating human embryonic cells for a cancer biology project, when he noticed that the cells stopped dividing after about 50 divisions. What was surprising was that other cells stopped dividing at the same time. This phenomenon was later called the “Hayflick limit”.
According to Hayflick, the discovery defies a "60-year-old assumption" that normal human cells can proliferate endlessly. Hayflick was mocked for a decade after releasing his Experimental Cell Research in 1961, after a work he co-wrote with colleague Paul Moorhead was rejected by a major scientific publication.
"With amazing scientific discoveries, it was business as usual." Initially, the discoverer is mocked, but once someone says, "It might work," it is accepted, according to Hayflick.
Scientists increasingly believe that aging can be beneficial. Its emergence was most likely caused, at least in part, by cancer cells' efforts to limit their ability to divide in order to slow their growth. This is something that happens frequently in our lives. Senescent cells have an impact on wound healing, fetal development, and labor and delivery. When these events occur, the senescent cells build up in the body.
"Your immune system recognizes and destroys them when you're young," Perez explained. "However, as we become older, our immune system activity declines and we lose the ability to eradicate them."
Senolytics are investigational medications that selectively kill senescent cells. The Mayo Clinic has multiple patents. Experiments with rats revealed that they could prevent or lessen a variety of age-related diseases.
The potential benefits are only now becoming apparent. At least a dozen clinical trials using senolytics are under underway to determine whether they can assist reduce the progression of Alzheimer's disease or improve bone health.
Senolytics are dietary supplements that are already available from some companies. However, scientists claim that they have not been proven to work or to be safe. They are labeled 'promising'.
According to Labrasser, who directs the Mayo Clinic's Center for Aging, exercise is "the most promising instrument we have" for supporting healthy aging.
According to research, it prevents the accumulation of senescent cells.
Soler claims that exercise permits him to function normally even at his elderly age.
“Exercise as much as you can,” he advises. “Staying healthy should be everyone’s goal.”