Communicating nutrition findings: why one study is never enough

You are reading a nutrition article with a catchy title (e.g. " X food cures Y") and you reach a sentence similar to "according to one study by x research group ". Please read a little further and answer this... are the arguments in that article based solely on that ONE study? Articles that do this do not have a strong scientific basis for the statements they are making. Sounds a little bit contradictory doesn´t it? I mean, they are citing one scientific article! Unfortunately, in research, one study is not enough.

Why is one study not enough? Well, one important aspect is that researchers have to be sure that the findings can be replicated. For example, if the study of one research group found that a particular food lowers cholesterol levels; then the ideal thing would be that further studies (even from other research groups) find the same effect. It does not always happen this way, unfortunately. It could be that there was a difference in the materials/products used, that there was information missing in the report of the previous study that prevented a new group from replicating it identically or maybe that there was some kind of human error in the analysis of the samples/data. The possibilities are endless. It is actually part of the researcher´s job to mention the reasons why he/she believes the findings could not be replicated when reporting the results of the new study. This way other researchers can avoid making the same "mistakes" when designing future studies.

Findings that have been replicated by various studies provide a strong scientific basis when talking about nutrition (and almost any other field of study you can think of). Of course, there are other things that are important (e.g. how many participants took part in the studies, which methods were used, etc). However, it is already a good start if the article mentions similar findings among different studies or if the expert interviewed mentions something along those lines. If that is not the case...well...it may be novel, but it still needs to be studied more before reaching to any conclusions.

Luz