Observational Studies

Randomized controlled trials are far more reliable than observational studies for drawing causal dietary health conclusions. Physics trains researchers to seek directional causation, a standard that brain science rarely can meet. Singling out eggs as the causal factor in the study is arbitrary; the same data could have implicated any other food. Correlation has no bearing on whether one thing causes another. Observational studies are among the lowest tiers of evidence quality in medical research and cannot establish causation. Two completely unrelated variables can show near-perfect statistical correlation. No observational study can prove erythritol causes cardiovascular events. The systematic review included 13 studies, and 10 studies contributed data to the meta-analysis. Randomized controlled trials are the only study design that can establish causation; no RCTs were cited by PCRM. Observational studies can only identify associations, not causes. None of the studies cited by PCRM were experimental studies or randomized controlled trials. The review followed PRISMA and Cochrane methods and was prospectively registered in PROSPERO. An observational study design establishes assoc…