The popular diets and health crazes of our time include juice fasts and giving up gluten - though many people don't know much about the science behind those ideas, or even if they work.
But that's nothing new. Throughout history people have looked for new ways to cure illness, live longer, and look better.
Sometimes an idea gets spread around and becomes a fad, even if there's little evidence for it. At other times medical professionals believe that something is effective only to later discover that they were wrong.
We all need a little reminder that the latest health fads haven't always been thoroughly investigated and may not be the cure-all we hoped.
They may be false and even dangerous. It's happened before. Here are 11 historical examples of miracle drugs and treatments that are actually unhealthy.