Vladimir Putin and Xi Jinping were caught on a hot microphone speculating about whether medical advances such as organ transplants could extend human life well beyond 150 years – or even make immortality possible. Their conversation, recorded during a summit in Beijing, has sparked questions about how close science is to defeating ageing.

While the idea of humans living forever remains firmly in the realm of speculation, researchers are making significant progress in understanding why we age and how the process might be slowed. Experts point out that there is currently no evidence that immortality is achievable, nor agreement on whether there is a fixed biological limit to human lifespan.

Despite major advances in medicine, no one has surpassed the longevity record set by Jeanne Calment of France, who died in 1997 at the age of 122. Some studies suggest that mortality rates level off at extreme ages, but others caution that records of such longevity can be unreliable.

The notion of replacing organs to extend life is seen as highly unrealistic. Scientists warn that repeatedly transplanting organs would be physically traumatic and that ageing affects far more than just organs, involving bones, tissue and other complex systems of the body.

Nevertheless, the field of longevity research is attracting vast investment. Russia has launched a multi-billion-ruble programme in regenerative medicine, while Silicon Valley entrepreneurs continue to fund experimental anti-ageing projects. Some wealthy individuals have even turned themselves into test subjects for new treatments. Mainstream researchers, however, stress that many of these attempts lack scientific rigour and could be unsafe.

One area of serious interest is epigenetics, which looks at how genes switch on and off without changing DNA itself. This process appears to break down over time and may be central to ageing. Laboratory work with the drug rapamycin has extended the lives of animals, though there is no evidence it would have the same effect on humans.

For now, scientists argue that efforts should focus less on fantasies of immortality and more on improving the number of years people spend in good health.