The Problem With Epidemiology

In the western world for 70 years we've been told that meat is bad for us so who eats meat the people that smoke drink ride motorcycles and do other rebellious things. The problem with epidemiology is it can't tell us if we're seeing a healthy user bias meaning the people who eat plants are doing all the other healthy behaviors right playing tennis more in sun higher socioeconomic status or whether the plants are really beneficial but I think the fact that there's so much conflicting evidence across epidemiology studies is not a very good thing to base any decision on.