Editor's note: Aaron E. Carroll is a professor of pediatrics at the Indiana University School of Medicine and the director of its Center for Health Policy and Professionalism Research. He blogs about health policy at The Incidental Economist and tweets at @aaronecarroll. The opinions expressed in this commentary are solely those of the author.
Recently, a study published in the British Journal of Nutrition said that organic fruits and vegetables are more nutritious.
A press release declared it the "largest study" of its kind. Because of its size and breadth, some people believe that it trumps previous research which showed organic food did not appear to be any safer or more nutritious than conventionally grown food.
This new study, like many before it, was a systematic review and meta-analysis. That means it wasn't a new clinical trial or report of laboratory research. It was a specific kind of analysis that allows for a "study of studies." Basically, researchers set out to find all relevant research in a field, and then combine all of it together into one big analysis.