For generations, our ancestors have relied on word-of-mouth recommendations for much of their health care. The official name for this type of information is anecdotal evidence . For example, Aunt June tells you that feverfew has cured her migraine headaches, or your brother Bob describes the miraculous results he got by taking glucosamine and chondroitin for his painful shoulder.

Although definitely not solid scientific evidence, anecdotes can be quite valuable. In many cases, it is through such practical experience that we first discover the treatments that are worth investigating. However, only properly designed double-blind trials can really tell us whether a treatment is effective. In medicine, anecdotal evidence is notoriously unreliable.