Millions of people are sending off their DNA to companies like Ancestry.com and 23andme to find out where they come from, and what diseases they might get. But how much can you trust these DNA kits? To find out, we speak to anthropologist Prof. Jonathan Marks and geneticist Dr Adam Rutherford.

Check out the full transcript here: http://bit.ly/2OSICOD

Selected references: This academic paper on genetic ancestry testingAncestry.com’s white paper The genetics of Alzheimer DiseaseA perspective piece on genetic privacy

Credits: This episode was produced by Rose Rimler, with senior producer Kaitlyn Sawrey… with help from Wendy Zukerman, Meryl Horn and Michelle Dang. We’re edited by Blythe Terrell. Fact checking by Michelle Harris and Michelle Dang. Mix and sound design by Peter Leonard. Music by Peter Leonard, Frank Lopez, Emma Munger and Bobby Lord. Recording assistance from Cole del Charco, Madeline Taylor, Carmen Baskauf, Ian Cross and [Mareek] Marijke Peters. A huge thanks to everyone who spat in a tube for us, especially Toni Magyar and Alex Blumberg, and to all the researchers we got in touch with for this episode, including Dr. Wendy Roth, Dr Deborah Bolnick, Dr Celeste Karch, Professor Nancy Wexler, Dr. Robert Green, Dr Catharine Wang, and others. Thanks also to the teams at Ancestry.com, 23andMe, and MyHeritage. Thanks to the Zukerman Family and Joseph Lavelle Wilson.