Hi readers,
This week, I went to the First Conference on Human Enhancement, a small, invitation-only medical meeting at the UK’s House of Lords, about ways to extend our lifespan and “healthspan” – keeping people in good health as they age for longer.
I was hoping to hear about some innovative anti-ageing research, as some of the speakers and delegates came from the more unconventional side of this field. They included Zoltan Istvan, founder of the US Transhumanist Party (which aims for human immortality), who has occasionally written articles for New Scientist, and people promoting the Enhanced Games, a planned counterpart to the Olympic Games where drug doping would be not only allowed, but encouraged.
To my disappointment, most of the science turned out to be fairly familiar – and some of the anti-ageing strategies discussed could be generously described as early-stage research that doesn’t yet have a strong evidence base.
For instance, there were researchers promoting the use of hyperbaric oxygen chambers, intermittent fasting and mega-doses of supplements. To my knowledge, none of these strategies has been shown to have beneficial effects on lifespan or healthspan in randomised trials, although they get hyped a lot in anti-ageing circles.
In a session on neurological enhancement, it turned out that most of the speakers recommended taking psychedelic drugs, such as ecstasy or psilocybin, the active compound in magic mushrooms, to boost mental functioning or combat mental health problems.
As a mental health treatment, the approach has some supporting evidence. For instance, ecstasy may help people with post-traumatic stress disorder, while psilocybin is being investigated for assisting with depression.
Psychosis risk
But critics say that, here too, the evidence is being overhyped and media coverage can lead to self-experimentation that occasionally triggers psychosis. Neither strategy has strong support from large-scale clinical trials, like the ones mainstream antidepressants have to be tested in.
The most eye-opening talk for me was by David Gems, a biogerontologist at University College London. He said that among mainstream researchers, optimism about cracking the problem of ageing is lower than it has been for some time.
That’s because several anti-ageing strategies that initially seemed promising have had setbacks. One issue is that approaches found to dramatically extend lifespan in tiny nematode worms – by up to tenfold - seem unlikely to work in people. The reason is that we now know that nematodes have an unusual strategy of reproducing only once in their life: they suddenly put all their energy and resources into sexual maturation and die soon afterwards.
It is unsurprising that blocking this dramatic sexual maturation process leads to longer-lived worms. But most animals, including humans, are built to reproduce many times in their lives and so the same anti-ageing strategies are unlikely to work.
Calorie restriction
There have also been longevity claims made for calorie restriction, where people eat about 30 per cent fewer calories than the recommended amount through carefully chosen and weighed-out meals.
Calorie restriction gives impressive results in extending lifespan for nematode worms, yeast cells and some (but not all) strains of laboratory mice. But when applied to a species closer to humans – rhesus macaques – it does make the monkeys thinner and improve certain health markers, such as their cholesterol levels, but it doesn’t make them live longer.
Randomised trials of calorie restriction in people are impractical as they would take decades to observe any effect on lifespan. Short-term trials have looked at whether the strategy affects blood tests that are claimed to measure the rate of ageing. These have been inconclusive.
But one thing calorie restriction definitely does achieve is making people thin. So the claim that it increases lifespan seems incompatible with the recent realisation that older people who are just a bit overweight tend to live longer than their peers who are classed as being at a healthy weight, perhaps because having some padding means they have more energy reserves when they get ill.
Gems argued that rather than researchers rushing to give advice for how people can slow the ageing process, they should instead be focusing on understanding the mechanisms behind ageing. “Only when we have done so will the time be truly ripe for translational research,” he said.
