Introduction

Dr. Michael Greger: While randomized controlled trials are highly reliable and assessing interventions like drugs, they're harder to do with diet. He says we have to use observational studies of large numbers of people and their diets over time in order to see which foods appear to be linked to which diseases. But even if observational trials did provide lower quality evidence, maybe we don't need the same level of certainty when telling someone to eat more broccoli or drink less soda compared to whether or not you want to prescribe someone some drug.