If the only two certainties in life are death and taxes, Indonesian native Sodimedjo must have been laughing throughout his tax-free retirement until his recent death at a claimed age of 146. There’s just one problem with that – his age might not be true. Indonesia didn’t start keeping official records until 1900, and the man in question claims to have been born in 1870. Officially, the oldest living human in history was Frenchwoman Jeanne Calment, who died in 1997 aged 122. Just over 1,100 people are verified as having lived to 111 or older, which isn’t many out of the 107 billion people who are estimated to have ever lived, according to the Population Reference Bureau.
Yet Sodimedjo still raises the question: can humans live beyond 146? Which poses another question: when? RISING spoke to Richard Faragher, professor of biogerontology at the University of Brighton, to find out the answers…
RISING Could Sodimedjo have made it to 146?
PROF RICHARD FARAGHER ‘This sort of story crops up a lot and I don’t believe it. It’s so hard to believe it in societies with such poor birth records. Some cultures fete older people, so they add years to their life in the way we in the West try to knock some off.’
RISING So how old can humans live to be?
RF ‘There is quite simply a decline in the organ system over time that means, as things stand, without intervention, humans are unlikely to live much beyond 120, because that’s the oldest person we know of that we can verify.’
‘In terms of getting more of us to 100 and beyond, better healthcare is the biggest factor, particularly getting people to stop smoking’
RISING So, intervention: we can think of three factors that would influence lifespan; genetics, lifestyle and environment. Which is the most important?
RF ‘It’s a combination of all three, but some genes do have a big influence on lifespan. For example the FOXO3a gene has been strongly linked with human longevity. In terms of getting more of us to 100 and beyond, better healthcare is the biggest factor, particularly getting people to stop smoking. Smoking is an unalloyed killer. Obesity is also an issue – we’re exercising less and our houses are better insulated. That latter point alone could add two kilos in body weight. Personally I believe pollution is less of an issue. Air quality is better than it has been at any time since the Middles Ages – that’s 500 years ago.’
RISING Is there anything else we can be doing now to ensure we live longer?
RF ‘A genome ‘snip’ SNP test is a good place to start. This will give you an idea of your genetic make-up and the conditions you may have or are prone to have. It can also tell you whether you’re better suited to a low-carb or low-fat diet, which is important if you’re trying to lose weight. There’s no such thing as a healthier diet – it’s what works for you, and that’s genetically predetermined. Genome testing is molecular biology’s greatest success and will improve health.’
RISING We read that research in the Netherlands has discovered a peptide can be used to destroy cells that play a role in ageing in mice – ‘senescent cells’ that lose the ability to replicate and destroy themselves, so hang around damaging healthy cells?
RF ‘This is a big discovery, because senescent cells definitely play a role in ageing in humans.’
‘There’s nothing different between fixing cystic fibrosis and lengthening life, but humans see the two propositions as different’
RISING So what’s the next step? Manipulating genes to extend human life, perhaps?
RF ‘That’s what gene therapy is all about. There are 6,000 genetic diseases that need fixing. Conceptually, there’s nothing different between fixing cystic fibrosis and lengthening life, but humans see the two propositions as different. It’s values-based, not science-based. Let me ask you this: do you see death as a disease or a natural process?’
RISING Well, a natural process.
RF ‘Now let’s say everyone on the planet has scurvy and dies. Is that a disease or a natural process?’
RISING It’s, er… oh.
RF ‘Exactly. We can cure scurvy with orange juice and no one complains about the ethics, but science will be attacked for trying to cure death.’
RISING And how far off is that? OK, not a cure for death, but humans living past 146?
RF ‘Look at it this way: imagine an 80,000-year-old cave painting. Imagine that the human who created it said, “One day people will be able to travel faster than they can on horses,” and his mate turns to him and says, “Nah.” The first human was right, but for nearly 79,900 years he was wrong. Progress isn’t a law of nature. So could humans live for an infinite period of time? Not tomorrow, no. In a million years? Possibly, but that’s no use to us. In 30 years? Maybe, but when you look at our past predictions of the future humans have a habit of being spectacularly wrong. In one book from the 1970s the planet was girded by a huge network of tunnels that allowed you to travel as if on a train and stop at stations to use a call box. Instead we now walk around with mobile phones that give us access to the knowledge base of the entire human population. And pictures of cats. So I’m sure that one day humans will live to 146, but none of us can say when that will be.’
WHAT NEXT? Watch Richard Faragher discuss the cost of ageing, in both human and financial terms – and why a drug that slows down the ageing process could help us live longer and save money.