Whilst life expectancy is declining in the UK and America and other high-income countries, some tech billionaires have become obsessed with life longevity - but which factors really impact how long we live and when we die?

Public health expert Devi Sridhar speaks to Krishnan Guru-Murthy on Ways to Change the World about the launch of her new book 'How not to die (Too Soon).

She explains how changing our public health policy could improve life expectancy, what the UK can learn from other countries when it comes to health, and what her own cancer diagnosis taught her about the state of the NHS’ waiting list times.

Once described as the 'comedian's comedian' Stewart Lee has been performing stand up since 1988.

He is known for pushing boundaries with his intelligent, self-referential and often provocative style of comedy but in his new show 'Stewart Lee vs the Man Wulf' he questions his place on the comedy circuit in an era of increasing populism rhetoric and the popularity of, in his words “$60m Netflix comedians of hate.”

In this episode of Ways to Change the World with Krishnan Guru-Murthy he discusses the state of comedy today and what he thinks of the comedy style of comics like Ricky Gervais and Dave Chappelle as well as why he wouldn't tour America right now.

As The Observer, the world's oldest Sunday newspaper begins a new era under Tortoise media he also reflects on his column for the paper which he's stopped after 15 years.

Produced by Holly Snelling and Sachin Croker

Newly appointed National Theatre Director Indhu Rubasingham becomes the first woman and person of colour to lead the theatre in it's 60 year history.

She sat down with Krishnan Guru-Murthy to discuss art, diversity and censorship and taking on her 'dream job.'

Produced by Holly Snelling and Vik Patel.