Jennifer Richler posts a good piece about what to expect from good popular science writing—and what to expect from yourself, the reader.
…when you finish reading a piece of science writing, you [should not] think, “‘Wow, I better make some serious changes to the way I eat/talk to my children/use my credit cards,’ but rather ‘Hmmm, I wonder how likely it is that this advice will turn out to be worth following.’” That curiosity should spur you to seek out good information continually. Over time, if the research appears to converge on a particular conclusion—the overwhelming consensus that there is no link between autism and vaccines, for example—then you should probably take it seriously.