I walk towards the door of the Longevity Medicine Institute gripped by a sense of impending doom. Inside this terraced house on a quiet street in Sydney’s Double Bay, a team of experts is poised to cast a merciless eye over my human frailties. I’m going to confront my mortality in one of the most exacting health assessments around.

“Longevity” is a buzzword so overused that it almost makes you lose the will to live. Yet, there’s no getting away from the fact people are going to ever more extreme and often dubious lengths to ward off the Grim Reaper. Take the American tech billionaire Bryan Johnson, who, among other extreme practices, injects himself with blood plasma from his teenage son in an effort to reverse the ageing process.