In June this year, a patient in the United States received an unusual injection. It was the first time a cellular reprogramming treatment, which turns back the clock of aged cells toward youth, had been administered to a human being. Because it was a Phase 1 safety trial involving injection into the eyes of patients with optic nerve disorders such as glaucoma, it is too early to call it a rejuvenation shot. Still, the reversal of aging, until now confined to animal experiments, has finally been put to the test in humans.
The desire to live long is as old as human history. Qin Shi Huang, who unified China, searched in vain for an elixir of immortality and died at 49. Some 2,200 years later, humanity is challenging aging in an entirely different way. Capital is flowing into the longevity industry, centered on Silicon Valley, covering the removal of senescent cells, gene and cell therapies and regenerative medicine, while research using artificial intelligence to measure the pace of aging and predict disease risk is also active.
Caution is of course warranted. Reversing the age of a cell and reversing the aging of a person are problems of a different order. Long-term safety must also be verified, including whether cells restored to a younger state turn cancerous. Even so, it is a significant shift that medicine, which has treated age-related diseases one by one, is now trying to control the mechanism of aging itself.
Over the past century, humanity achieved remarkable progress through the extension of lifespan alone. The official record for the longest life is 122 years, held by Jeanne Calment of France. The change in South Korea has been even more dramatic. Life expectancy, which stood at 62 years in 1970, rose to 83.7 years in 2024. The gains came from nutrition and sanitation, vaccination and antibiotics, health screenings, and advances in the treatment of cancer and cardiovascular and cerebrovascular disease. Cancer no longer means imminent death. The five-year survival rate for cancer patients in South Korea has reached 73.7%.
Behind the statistics on lifespan, however, lies a number that draws less attention: healthy life expectancy, the period lived without disease or disability. In 2024, healthy life expectancy for Koreans was 64.6 years for men and 66.4 years for women, actually down from a year earlier. That leaves about 16 years for men and 20 years for women lived with illness. Lifespan has grown, but so has the time spent unwell, and this coexistence of longevity and disease is our reality today.
The important question now is not how long, but in what condition the added time will be lived. Even if one lives to 100, it is hard to call longevity a blessing if the final 20 years must be spent dependent on others because of dementia or the aftereffects of a stroke. For the individual it is a matter of dignity, for the family a burden of care, and for the country it leads to rising medical and long-term care costs.
The goal of health policy must therefore shift from extending lifespan to extending healthy lifespan. By this measure, old age is healthy if a person can manage conditions such as hypertension or diabetes well, walk and think for themselves, maintain relationships and decide the course of their own life. What is needed is a change of perspective that looks at healthy life expectancy in terms of physical and cognitive function and the capacity for independence, rather than the mere presence or absence of disease.
Fortunately, much is already known about how to extend healthy life expectancy. Heart attacks and strokes in one's 70s can only be prevented by managing blood pressure, blood sugar, cholesterol and smoking from one's 40s and 50s, and the risk quietly accumulates from one's 20s and 30s. Dementia and frailty likewise do not arrive overnight. Exercise and nutrition, hearing and cognitive function, sarcopenia and social isolation all require management across the entire course of life. An injection that returns cells to a younger state will not also restore blood vessels damaged by smoking and high blood pressure. Longevity technology becomes meaningful only when it is added on top of these basics.
Another question is who the technology reaches. If expensive longevity technology becomes the privilege of a select few, a new health gap will emerge in which even living long in good health is divided along income lines. Technologies with proven effectiveness should be brought within the scope of public coverage such as national health insurance, and before that, the state should provide dense support for the prevention that anyone can practice.
The kind of longevity we want is clear. It is not the number 120, but time in which a person remains the master of their own life even at 100. If medicine over the past century opened an era of living longer, our task now is to create an era of living longer in good health. The true revolution in longevity does not lie in endlessly postponing death. It lies in living the added time in health and dignity.
