British Radio

Until recently, Bryan Johnson was paying hundreds of thousands of dollars to infuse one litre of his teenage son’s youthful plasma into his own ageing blood stream every month. “I’ve never paid more attention to what he’s eating … because that was going into my body,” the 46-year-old American tech entrepreneur says on new podcast The Immortals. He also pumped his own plasma into his 70-year-old father’s body to help improve his declining physical and cognitive health: “It was one of the most meaningful moments in his entire life. And it was the same for me.” Johnson continues to pay $2m a year for a research team to investigate how we can live longer – and he is certainly not the only rich guy in Silicon Valley dedicated to the search for eternal life.

“It took us ages to find somebody to talk to us,” says technology reporter and psychologist Aleks Krotoski, who hosts the BBC Radio 4 series. “Strangely, people who take the blood of the young are a bit reserved … ”