Tag Archives: Science

Is it really possible to live until you’re 146? The science of ageing

Scientists doubt that extreme natural longevity is feasible. But if lifespan is ruled by a genetic ‘clock’, that view could change

The grim reaper comes for everyone in the end, but sometimes he is in less of a rush. This was certainly true for Sodimedjo, an Indonesian man who died on Sunday, but whether he was the full 146 years he claimed remains doubtful – not least because his purported birthdate is 30 years before local birth records began.

Scientists have their own reasons to be sceptical. A study published last year pointed to the existence of an upper ceiling on the natural human lifespan.

While the average life expectancy has steadily increased since the 19th century, data from the International Database on Longevity showed that the age of the very oldest people on the planet appeared to plateau in the mid-1990s – at a mere 114.9 years. Since the apparent plateau happened at a time when the reservoir of healthy centenarians was expanding, scientists concluded that an intrinsic biological limit had been reached: even if you evade accidents and disease, your body will still steadily decline until it passes the point of no return, the data appeared to suggest.

This raises the intriguing possibility that ageing could be slowed or even reversed, and some animal studies have already claimed to do just this.

Jan Vijg, a geneticist at Albert Einstein College of Medicine in New York City, who led this research, said: “We simply provided evidence that humans do indeed have a ceiling that they really cannot go beyond. That’s part of being human.”

There will be the occasional outlier – the French supercentenarian and oldest woman to have lived, Jeanne Calment, was 122 when she died in 1997, but most of us have a shorter intrinsic “shelf life”. The probability of someone living to 146 is infinitesimal, Vijg said. “If somebody told you that they saw a UFO yesterday but it’s gone now, you’d probably be polite, but you wouldn’t believe it,” said Vijg. “That’s my reaction with this story.”

Before resigning yourself to the knowledge that you will almost certainly expire by the time you reach 115 years, it is worth noting that this ceiling could be moveable in the future.

Richard Faragher, professor of biogerontology at the University of Brighton, puts it this way: How long can a human live if you don’t do anything to them? Probably around 120. But there is a separate question, how long do people last if you can do something to them?”

Until now, the steady increase in average life expectancy (as distinct from lifespan) has been driven by fewer people smoking, better nutrition and antibiotics. Drugs and surgery for heart disease and cancer have also played a part.

However, scientists are only just beginning to explore the possibility of therapies designed to target the process of ageing itself, as well as the illnesses that come with advancing years. This field has recently taken an intriguing twist, as evidence has emerged that ageing is not simply the manifestation of environmental wear and tear. Instead, the latest work suggests that ageing is at least partly……….Read more here!

Courtesy of Guardian News & Media Ltd

 is the Guardian’s Science correspondent. Follow Hannah on Twitter @hannahdev

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What can a simple fruit fly teach us about ageing?

A recent study could lead to interventions that extend human lifespan and improve health in our later years. Based on new evidence regarding a DNA-based theory of ageing, this field aims to attenuate diseases of ageing such as cancer, hypertension and Alzheimer’s disease.

Ageing research dates back many years, but thanks to scientists at the Buck Institute for Research on Aging the field has become more widely recognised. Researchers at Buck coined the term ‘geroscience’ to explain the relationship between ageing and age-related diseases. The notion that people are more susceptible to diseases as they grow older rings true to most of us, although some older adults lead healthy and active lives without medical intervention.

“Every day, 10,000 Americans turn 65, and every day, more and more of them are just as fit as me” – so says Linda Marsa, contributing editor at Discover magazine. Richard Johnson, an economist, says “Today’s seniors are healthier, better educated, and more productive than ever.” Despite these positive trends, many would argue that the goal of geroscience – to explain and intervene in age-related diseases including arthritis – remains highly relevant to today’s societies.

Since life extension studies remain inconclusive, scientists are working to improve ‘healthspan’ – the length of time a person is healthy, especially in the later years. Brown University Professor Dr. Stephen L. Helfand is one of several researchers whose work is advancing the rapidly maturing field of ageing science. He is also senior author of the study mentioned above.

This study showed that many transposable elements (TEs) become activated with age in the fruit fly Drosophila* and that this activation is prevented by dietary restriction – an intervention known to extend lifespan. TEs are sequences of DNA (our genetic material) that move (or jump) from one location in the genome to another. Drosophila is a small fruit fly used extensively in genetic research. Why do scientists use fruit flies? Because fruit flies share 75 percent of the genes that cause disease with humans including having a smaller, fully-sequenced genome for easier genetic manipulations. Ultimately, the study provides evidence that preventing TE activation by dietary restriction may be a useful tool in ameliorating aging-associated diseases. The hope is that such results could be applied to humans as research progresses.

“Our demonstration that dietary [restriction], genetic and pharmacological interventions that reduce the age-related increases in [transposon] activity can also extend lifespan suggests new and novel pathways for the development of interventions designed to extend healthy lifespan.” according to this study. Despite the possibility of a true causal relationship, scientists can (happily!) avoid misleading phrases such as the Fountain of Youth, since geroscience hopes to improve health and longevity – not provide some mythical youth potion. Older people are a rapidly growing demographic – by 2100, the number of people aged 60 and over will reach 3.2 billion. It is, therefore, vital that researchers use terms that do not marginalize an increasingly growing demographic –  or maintain the current narrative of our youth-obsessed culture.

We have seen major breakthroughs in public health and medical research, including a generational leap in longevity, the use of antibiotics, the completion of the Human Genome Project, and more. Society has also reaped the benefits of new medical technologies and advances in nutrition such as sustainable diets, virtual reality, and food scanners. As the field of geroscience continues to evolve, both public and private sectors may increase investments for ageing research, especially if it can reveal treatments for conditions that afflict older people. More data is also needed to understand and support research findings including the current study by Dr. Helfand. This paper comes as scientists from three universities including, Brown University, New York University and the University of Rochester forge a new partnership in DNA-related research. The collaboration is supported by a five-year, $9.67-million grant from the National Institutes of Health. Hence, study outcomes could have a lasting effect on health and society. David Sinclair, a researcher of ageing at Harvard Medical School, has put this attitude into words: “The goal of this research is not to keep people in the nursing home for longer. It’s to keep them out of nursing homes for longer.”