Why does Trump think paracetamol causes autism?

US President Donald Trump has told women they shouldn't take paracetamol (also known as Tylenol or acetaminophen) during pregnancy because it has been linked to autism. We unpack the evidence with experts — where has this claim come from? Have we really found a treatment for autism spectrum disorder? And what are the dangers of taking health advice from Trump?Also, an unexpected result from a study looking into whether a yoga exercise program could prevent falls in older adults.