Joe Rogan was left speechless after learning a bevy of disturbing realities about Americans' health on the latest episode of his wildly popular podcast.

Rogan had on two Stanford-trained doctors who reeled off more than a dozen facts about cancer, dementia, autism, infertility and the amount of chemicals in people's bodies in the US.

Among the most alarming was the fact America is leading the world for cancers in young people and that early-onset dementias have tripled since 2012. The veteran podcaster was stunned to the point of silence but could be heard letting out periodic 'wow's' and heavy exhales.

One of the doctors, Dr Casey Means, a head and neck surgeon from Oregon, said: 'We are getting destroyed, and it's very recent and it's accelerating. The stats speak for themselves.'