Researchers find a way to mimic clinical trials using genetics - MIT Technology Review

They noted that epidemiology has an admirable track record in identifying the causes of infectious diseases from AIDS to Zika, in part because hypotheses can be tested in laboratories and in the field, and because governments have been easily convinced to do such tests. But chronic conditions like heart disease and cancer present an entirely different challenge. Epidemiology can provide correlations between diet, lifestyle, and disease, but that’s all it does. It generates hypotheses about possible causes, and little more than that. What concerned Davey Smith and Ebrahim was that epidemiologists had taken to jumping the scientific gun: they were advising people how to live and eat on the basis of mere hypotheses, without doing the rigorous (and very expensive) trials that might determine whether they were right.