What matters is not whether someone famous recommends a particular product, but whether there is evidence from randomised controlled trials showing that it is more likely to do good than harm. Assessing medical research can be complex - even for the experts. It helps to understand some of the more common pitfalls. Anecdotal evidence can be dangerous. You cannot infer a general rule from a single experience - especially someone else's.
Many diseases get better with or without treatment.
The placebo is powerful. This makes it difficult to discern the real effects of active treatments without randomised controlled trials. Screening tests that detect early disease are not always beneficial. They can lead to people living more years with disease rather than leading longer lives. They vary in their opinions and approaches to managing the same conditions.