After all, it’s the first claim in any scientific endeavor that is most likely to be wrong. Only after that report is made public will the authors have the opportunity to be informed by their peers of all the many ways that they might have simply misinterpreted what they saw. The regrettable reality, of course, is that it’s this first report that is most newsworthy. So
be skeptical.
If the association appears consistently in study after study, population after population, but is small — in the range of tens of percent — then
doubt it. For the individual, such small associations, even if real, will have only minor effects or no effect on overall health or risk of disease.
If the association involves some aspect of human behavior, then
question its validity. If taking a pill, eating a diet or living in proximity to some potentially noxious aspect of the environment is associated with a particular risk of disease, then other factors of socioeconomic status, education, medical care and the whole gamut of healthy-user effects are as well. These will make the association, for all practical purposes, impossible to interpret reliably.
The exception to this rule is unexpected harm. ...