Eternal Life 7
August 12, 2011 § 1 Comment
Then came the breakthrough with telomeres. In January 2010 a study in Nature showed that it was possible to reverse extreme ageing in mice by increasing their levels of telomerase, the enzyme that maintains telomeres. Trying this in humans is risky, though. Mice make telomerase throughout their lives, but the enzyme is switched off in adult humans, to stop cells growing out of control. Raising our telomerase might slow ageing, but send our cancer risk soaring.
And telomerase can’t be the whole story. The world’s longest-lived rodent is Africa’s naked mole rat. It can live up to 30 years, five times more than biologists would expect from its body size. But the rats have short telomeres. Suddenly the picture starts lto look very confusing. Worse still, scientists recently found more than 70 genetic variants in humans that may be linked to longevity. “This is a very complex puzzle,” says Dr Thomas Perls, the Boston University scientist who found the genes by studying hundreds of centenarians.
Up until now we have to thank two far more basic things for improving our true longevity: sanitation and basic medicine. During the Roman Empire, our life span averaged 25 years. By the Middle Ages it increased to 33 years. During the second half of the 20th century we gained almost 30 years, doubling all our previous gains. But now we want more. Not just more years, but more youth.
Enter the pioneers of truly futuristic methods for defying age, such as Dr Aubrey de Grey, a Cambridge-based co-founder of the California-based SENS (Strategies for Engineered Negligible Senescence) Foundation. Earlier this month this bearded sage explained his work to the Royal Institution in London. He thinks that it will give us a 50-50 chance of reaching the threshold of immortal youth in the next quarter century.
De Grey believes that we age because we steadily accumulate cell damage caused by our bodies’ everyday metabolic work — breathing, digesting, etc. If you can fix the damage with a battery of medical interventions, you can rejuvenate your cells to their predamaged youthful state. It’s like restoring a classic car to showroom condition, he says. De Grey reckons that if you did this once every 15 years, you could live unblemished to see your thousandth birthday. It is arguable whether this is an inviting proposition. It would involve seriously gruelling medical procedures such as chemotherapy, bone marrow transplants and stem cell replacements to do the work. Hardly like getting a brow lift.