Human extinction – what are the effects of living to 200 – is it possible?

A Japanese woman, recognised as the oldest person in the world, died early in the morning of Wednesday April 1, 2015, at the age of 117.

Experts put Japanese longevity down to the nation’s comprehensive healthcare system, the support of the community, encouragement to stay physically active until they are quite elderly, a sense of being part of a family and a healthy diet that has traditionally been heavy in fish, rice, vegetables and

Additional research has suggested that people who were in middle-age during the years of food shortages during the Second World War have subsequently enjoyed better long-term health than people who never had to go without.

But Yasuyuki Gondo, an associate professor at Osaka University who specialises in geriatric psychology, says there is much more to longevity than merely a good diet and advanced medical care

Aubrey David Nicholas Jasper de Grey is an English author and theoretician in the field of gerontology and the Chief Science Officer of the SENS Research Foundation. He is editor-in-chief of the academic journal Rejuvenation Research, author of The Mitochondrial Free Radical Theory of Aging (1999) and co-author of Ending Aging (2007). He is known for his view that medical technology may enable human beings alive today to live to lifespans far more than any existing authenticated cases.

De Grey’s research focuses on whether regenerative medicine can thwart the aging process. He works on the development of what he calls “Strategies for Engineered Negligible Senescence” (SENS), a collection of proposed techniques to rejuvenate the human body and stop aging. To this end, he has identified seven types of molecular and cellular damage caused by essential metabolic processes. SENS is a proposed panel of therapies designed to repair this damage.

So what would be the ratifications is a human could live to age 200?

So far as scientists know, the last hundred years have been the most radical period of life extension in all of human history. At the turn of the twentieth century, life expectancy for Americans was just over 49 years; by 2010, that number had risen to 78.5 years, mostly because improved sanitation and basic medicine. But life extension doesn’t always increase our well-being, especially when all that’s being extended is decrepitude. There’s a reason that Ponce de Leon went searching for the fountain of youth. If it were the fountain of prolonged dementia and arthritis he may not have bothered.​

Humans as early as next year, following a key discovery that saw the ageing process reversed in mice. The study, involving Harvard University and the University of NSW, discovered a way of restoring the efficiency of cells, completely reversing the ageing process in muscles.

Two-year-old mice were given a compound over a week, moving back the key indicators of ageing to that of a six-month-old mouse. Researchers said this was the equivalent of making a 60-year-old person feel like a 20-year-old.

It’s hoped the research, published in Cell, will be expanded to humans as early as next year, with scientists set to look at how the theory of age reversal can be used to treat diseases such as cancer, dementia and diabetes.

The research focused on an area of cells, called mitochondria, which produce energy. Over time, the communication between this area and the cell nucleus degrades, leading to the ageing process.

Researchers injected a chemical called nicotinamide adenine dinucleotide, or NAD, which reduces in the body as we age. The addition of this compound led to the radical reversal in the ageing of the mice.

Over the past twenty years, biologists have begun to set their sights on the aging process itself, in part by paying close attention to species like the Lobster, which, despite living as long as fifty years, doesn’t seem to age much at all. Though some of this research has shown promise, it’s not as though we’re on the brink of developing a magical youth potion. Because aging is so biologically complex, encompassing hundreds of different processes, it’s unlikely that any one technique will add decades of youth to our lives. Rather, the best we can hope for is a slow, incremental lengthening of our “youth-span,” the alert and active period of our lives.

Some ethicists have pointed out that death is one of the major forces for equality in the world, and that welfare disparities will be worsened if some people can afford to postpone old age, or avoid it altogether, while others are unable to.

There is research available and concerns when scientists develop any kind of medicine or any kind of technology—the concern that these things are going to widen welfare gaps. The story of industrialisation is that the people who could afford the cars and machines and factories in Western countries were able to produce a lot more and generate a lot more wealth than people in poorer agrarian economies. That’s a serious issue. It’s probably true that if people in the first world were, through some sort of medical intervention, able to live to be 200 years old and people in Bangladesh were still dying at a relatively young age, that would tend to widen the distance in personal wealth.

So how will employers, government and financial service organisations deal with an aging population?

Older people also report, to pollsters and psychologists, a greater sense of well-being than the young and middle-aged do. By the latter phases of life, material and romantic desires have been attained or given up on; passions have cooled; and for most, a rich store of memories has been compiled. Among the core contentions of the well-being research of the Princeton University psychologist Daniel Kahneman is that “in the end, memories are all you keep”—what’s in the mind matters more than what you own. Regardless of net worth, the old are well off in this sense.

Should large numbers of people enjoy longer lives in decent health, the overall well-being of the human family may rise substantially. In As You Like It, Jacques declares, “Man in his time plays many parts, his acts being seven ages.” The first five embody promise and power—infant, schoolboy, lover, soldier, and success. The late phases are entirely negative—pantaloon, a period as the butt of jokes for looking old and becoming impotent; then second childishness, a descent into senile dependency. As life expectancy and health span increase, the seven ages may demand revision, with the late phases of life seen as a positive experience of culmination and contentment.

Further along may be a rethinking of life as better structured around friendship than around family, the basic unit of human society since the mists of prehistory. In the brief life of previous centuries, all a man or woman could hope to do was to bear and raise children; enervation followed. Today, life is longer, but an education-based economy requires greater investments in children—contemporary parents are still assisting offspring well into a child’s 20s. As before, when the child-rearing finally is done, decline commences.

But if health span extends, the nuclear family might be seen as less central. For most people, bearing and raising children would no longer be the all-consuming life event. After child-rearing, a phase of decades of friendships could await—potentially more fulfilling than the emotionally charged but fast-burning bonds of youth. A change such as this might have greater ramifications for society than changes in work schedules or health-care economics.

Regardless of where increasing life expectancy leads, the direction will be into the unknown—for society and for the natural world. Felipe Sierra, the researcher at the National Institute on Aging, puts it this way: “The human ethical belief that death should be postponed as long as possible does not exist in nature—from which we are now, in any case, diverging.