Twitter CEO Jack Dorsey appeared on a podcast with anti-vaccine fitness writer Ben Greenfield Tuesday, although he reportedly didn’t know Greenfield’s stance on the scientifically disproven theory prior to recording.
“Grateful for you,” Dorsey tweeted after recording with Greenfield. “Great conversation, and appreciate all you do to simplify the mountain of research focused on increasing one’s healthspan!”
Greenfield, who tweeted that the two discussed “advanced stress mitigation tactics, extreme time-saving workouts, DIY cold tubs, hormesis, one-meal-a-day,” and more, recently reinforced the theory that vaccines cause autism.
Studies have shown that there’s actually no link between vaccines and autism. Still, anti-vaccine propaganda continues to discourage parents from vaccinating their kids, leading the World Health Organization to list vaccine hesitancy as one of its global health threats for 2019.
A Twitter spokesperson later told TechCrunch that Dorsey did not discuss vaccines with Greenfield on the podcast, was not aware of his stance on them, and the appearance was not meant to be an endorsement of his beliefs.
Major social media companies have recently been making moves to prevent anti-vaccine propaganda from appearing on their sites. Facebook said it will not recommend these types of pages, Pinterest will not return any search for the word “vaccine,” and YouTube demonetized anti-vaccination videos.
Although Twitter has not made any changes specifically targeting this movement, its advertising policies regarding healthcare state “ads that make claims about the cure, treatment, diagnosis, or prevention of certain diseases and conditions are restricted under our Healthcare policy,” NBC News reports.