BBCDiary of a CEO host Steven Bartlett is amplifying harmful health misinformation on his number-one ranked podcast, a BBC investigation has found.Recent claims from guests – including that cancer can be treated by following a keto diet, rather than proven treatments – were allowed by the Dragons’ Den star with little or no challenge. Experts have told us failing to question these disproven claims is dangerous because it creates a distrust of conventional medicine.In an analysis of 15 health-related podcast episodes, BBC World Service found each contained an average of 14 harmful health claims that went against extensive scientific evidence.Flight Studio – the podcast production company owned by Mr Bartlett – said guests were offered “freedom of expression” and were “thoroughly researched”.The podcast launched in 2017 focusing on entrepreneurship and business. It soared in popularity as figures such as influencer Molly Mae and Airbnb founder Brian Chesky shared their tips for success.But in the past 18 months, Mr Bartlett has concentrated more on health, with guests presented as leading experts in their fields. Their views receive little challenge.The interviews are also posted to Mr Bartlett’s YouTube channel, which has seven million subscribers. Since this content shift last year, its monthly views have increased from nine million to 15 million.Mr Bartlett told The Times in April he expected his podcast to make £20m this year, mainly from advertising.YouTubeWe looked at the 23 health-related episodes released between April and November this year, fact checking – with four medical experts – 15 which contained potentially harmful claims.The experts we spoke to were cancer research professor David Grimes, public confidence in healthcare professor Heidi Larson, NHS diabetes adviser Dr Partha Kar and surgeon Dr Liz O’Riordan.We recorded harmful claims as advice that, if followed, could lead to negative health outcomes.In that eight-month window, some guests billed as health experts shared accurate information, but most were spreading misleading claims. These included:Anti-vaccine conspiracies, stating that Covid was an engineered weaponPoly-cystic ovarian syndrome, autism and other disorders can be “reversed” with dietEvidence-based medication is “toxic” for patients, downplaying the success of proven treatmentsPodcasters may claim they are sharing information, but they are actually sharing harmful misinformation, says Dr David Grimes from Trinity College Dublin.”That’s a very different and not empowering thing. It actually imperils all our health,” he says.Podcasts in the UK are not regulated by the media regulator Ofcom – which sets rules on accuracy and impartiality. So Mr Bartlett is not breaking any broadcasting rules.In a July episode, Mr Bartlett spoke to Aseem Malhotra, a doctor who became known during the pandemic for spreading misinformation about Covid vaccines.In the episode, Dr Malhotra says the “Covid vaccine was a net negative for society”. Analysis by the World Health Organization shows that it saved many lives during the pandemic.At the end of the episode, Mr Bartlett, who does not have a health background, justified the airing of the discredited views, saying he aimed to “present some of the other …