How Many Medical Researches Are There Publicin Journals?

In economics, you'd be taken to the coals if you didn't have a good natural experiment. Take for example, red meat. There are tons of studies that look at the relationship between red meat consumption and any number of outcomes. But it's hard to answer a question that people would want to know the answer to as, should i eat more or less red meat? Let's just try to answer it anyway.