The key lesson is that no single study is worth very much. Another study may have very different results due to differences in methods or random chance. To make sense of the latest study, someone with an understanding of the research needs to review it in the context of other existing knowledge. I say this as someone who writes a lot of things on the Internet and in non-reviewed forums, expecting people to believe me. Not As Well Supported As They Look A second important lesson is to recognize that most health findings are much less certain than reported.
Statistical tests have rules about how they can be used.
Those rules are seldom obeyed, resulting in gross overstatements of confidence. Most health researchers, let alone journalists or lay readers, do not realize this. Quite frequently, an exciting new discovery is due to random chance. While it is true that a study with 10 subjects can tell you very little about the average person, a study with 1,000 subjects may not tell you much more. These are serious problems and result in almost all health research claims being much less certain than is generally claimed.