Back in the 1990s eggs had an image problem. They are high in cholesterol, so the recommendations for intake were such that many people started avoiding them. Ergo, this commercial from the 1990s trying to convince kids that eggs are not the work of the devil. What was the science behind this? You can read the back story yourself.
But after all these years it turns out that in most people dietary cholesterol is not an issue. Eggs are now back on the menu according to the powers that be. The New York Times notes that it is a “a belated acknowledgment of decades of research showing that dietary cholesterol has little or no effect on the blood cholesterol levels of most people.” Decades. Let that sink in about how stubborn parts of the “scientific” establishment can be.
Science is a human endeavor. And some science is also much harder than other science. The “hard sciences” are different in many ways from the rest. The precision which physics is capable of is never going to be replicated in large domains of biology, of which medicine is the most relevant domain for the public. The issues are even more thorny when it comes to disciplines outside of natural science which manifest scientific aspirations. Here’s looking at you economics!
This is why I don’t like the “because science” meme. It should be “because science, for now.” Or, “perhaps, because science.” There is some science which is tried & tested, robust, and has not only withstood decades or centuries of critique, but yielded incredibly returns in practical domains. Think engineering. Then there are other sciences, such as much of nutrition, clinical psychology, and social science, which is important, but which offers answers which seem contingent on fads and fashions because of the proliferation of studies with low statistical power, or correlations which are ultimately just confounds. So what happens is the science does not shape opinions, opinions shape the science people choose.
On some level we all know this, but it is important to reiterate it. Like democracy science is the best that we have for a particular task. But in many specific instances it turns out to be really crappy. Because it’s hard, and nature is messy. Humility in science is a good thing. So is firmness of conviction, when it is warranted.