Snake oil? Scientific evidence for health supplements. It is really worthwhile to have a look at this chart – it presents the evidence for most of the oral supplements and their health claims. So, for instance,
there is good evidence that St. John’s Wort has a positive effect on mild to moderate depression. On the other hand, there is no evidence that garlic has any effect on anything.
However, it isn’t the content of this chart that’s interesting. What I do find heartening is the way in which it presents a lot of scientific research in a manner that is accessible to the lay person. The one problem with this chart is that it can’t present the size of the effect – St. John’s Wort may be useful in treating depression, but the chart doesn’t indicate how useful it is. So, the authors direct the reader to a Google documents spreadsheet that presents the results in text form and references to the research.
I followed up on the St. John’s Wort research and it, in turn, indicated the difficulty in doing useful psychiatric research.