How long can humans live? We ask an expert
Last year a study suggested there was a hard limit to the span of human life: 150 years. At this point, the study said, the body could no longer repair itself after illness. But how can we be sure? I asked Richard Faragher, professor of biogerontology at the University of Brighton and past chair of the British Society for Research on Ageing.
Even back in the 1700s, scientists were thinking about how far medicine could extend lifespan. Is 150 years the final answer?Modern humans have been on Earth for at least 200,000 years.
For most of that time, people have said: “No man shall ever travel faster than a horse” and been right. So to say that in 10,000 years we’ll reach no more than 150 is a big claim: it suggests that our 300 years of biology has found out everything.
That makes it sound as if there could be no upper limit.I’m agnostic on that. The talk at the moment is that breakthroughs that have been made in lower-model organisms – flies, worms, mice – may be translated into humans within about 30 years. Which would mean they could be applied to you. You could live to 100. A true optimist would say: we’ve managed to increase the lifespan of mice by 25%-38%. Roll that out to humans and, OK, it’s not quite 150 yet, but the techniques could be extended. I work in cellular senescence. When senescent cells build up in my skin, they give me wrinkles. When senescent cells build up in my bones, they give me osteoporosis. And we know that if you remove senescent cells from mice, which you can do with some genetic tricks, you see this big improvement in health.
What’s the pessimist’sview?Well, they’d say the rate at which breakthroughs in mice translates to humans isn’t great. I think this tells us that we need to be doing more studies.
Hang on … if disease is related to senescent cells, and we can get rid of those, doesn’t it follow we could get rid of disease entirely and – ouch! My brain
just exploded.Ha! Imagine the dawn of antibiotics. Maybe you’d say back then: “Antibiotics could get rid of all disease? Woah!”
I would definitely say that. I’d be there by candlelight, ear against the wireless, just spinning out …And I’d have to disappoint you by saying that penicillin didn’t get rid of all diseases. But something similar is starting to happen with ageing health: the emergence of a new medical industry akin to that of antibiotics. Great news for the costs to the NHS. The question is, which countries and companies will hold the patents and manufacture the compounds?
Would that mean only the wealthy will be able to extend their life? Actually, a lot of the interventions are quite cheap. One exciting drug is rapamycin. There’s good evidence that it may be an effective treatment for agerelated cognitive impairment. I’d like to see a scenario where, instead of someone saying: “I’m sorry I snapped at you. I have cognitive impairment, which will transition to full-blown decline within five years,” they would say: “Sorry I snapped. I went to the doctor and now
I have to take these tablets twice a day, and the queue is so long!” My goal is to convert a life-changing event into something where all we have to moan about is waiting at the pharmacy. And I think that is within reach.