The aging of modern world populations is a recognized problem. For instance, the growing ratio of retirees to workers challenges the economic viability of Social Security and Medicare. Of course, aging itself is highly problematic regardless of its economic implications; hence the fantasy of the fountain of youth.
Though no one expects explorers of remote jungles to stumble on the mythical fountain of youth, researchers continue seeking ways to ameliorate problems of aging and slow their development. Thus there is hope medical progress will continue to lengthen lives. One might envision living long enough to benefit from new medical advances that extend lifespan further, enabling survival until additional advances allow living even longer until still further advances allow yet further extension of life, a process that conceivably could accomplish immortality. That seems rather unlikely so long as the extension of life does not eliminate the gradual decline characteristic of aging. Moreover, with a body becoming forever increasingly decrepit without limit, it is not clear how long staying alive would be desirable.
Recently experiments, however, support the intuition underlying the old idea that bathing in blood of young people can have a rejuvenating effect. Even setting aside moral issues, bathing in young blood is unlikely to have any useful result. But a more radical variant of this tactic, circulating the blood of a young mouse inside the body of an old one, has been found to have a remarkable rejuvenating effect. Carl Zimmer’s 05/04/2014 New York Times article Young Blood May Hold Key to Reversing Aging sums up results of this research as follows:
Two teams of scientists published studies on Sunday showing that blood from young mice reverses aging in old mice, rejuvenating their muscles and brains. As ghoulish as the research may sound, experts said that it could lead to treatments for disorders like Alzheimer’s disease and heart disease.
“I am extremely excited,” said Rudolph Tanzi, a professor of neurology at Harvard Medical School, who was not involved in the research. “These findings could be a game changer.”
Looking for substances more abundant in the blood of young mice than old ones, Thomas Randow’s team at Stanford discovered a protein named GDF11 that, when injected into older mice, rejuvenated their hearts.
If treatments based on such substances prove capable of rejuvenating older humans’ tissues, reversing the ill effects of aging, immortality might become feasible. Given the remarkable advances in technology in recent times, often with results that earlier seemed inconceivable, and given the accelerating rate of technological progress, it would be foolish to take for granted that immortality cannot be achieved. But if such a fountain of youth is discovered, it can be expected to create enormous new problems, starting with immense worsening of already excessive population growth.