The New York Times recently published an interesting op-ed on the subject of salt. Its thesis is, first, that we have been and are being told by a variety of authoritative sources that we ought to consume less salt, second, that there is not and never has been adequate scientific support for that claim, and third that there is now evidence suggesting that the official advice is not merely mistaken but dangerous, that reducing salt consumption to the recommended level might well be bad for one's health.
What struck me about the piece was not mainly its contents—I had seen reports in the past on evidence that reducing salt consumption was bad for one's health—but its placement. I am not a regular reader of the Times, but my impression is that, in other contexts, it is sympathetic to arguments from official truth, arguments that start with some version of "all scientists agree that" and treat anyone who disagrees as either misinformed or in the pay of some interest group that wants the truth suppressed. Global warming is the obvious example, but I think there are others. So it was interesting to see them publish a piece debunking one version of that argument.
A close parallel to the case of salt is the case of saturated fat. A few decades back, the official wisdom, promoted by more or less the same sorts of authorities that now tell us to eat less salt, was that saturated fat was bad for the heart and one should therefor switch from butter to margarine. Further research eventually led to the conclusion that, while saturated fat was somewhat bad for the heart, trans-fats were much worse—and the margarine we were being told to switch to was made from hydrogenated vegetable oil, hence replaced saturated fats with trans-fats. In that case, as best I can tell, the official advice was not merely wrong but lethally wrong, a fact which led to less skepticism about official truth than it should have. Any readers better informed about the subject—nutrition is not an area where I can claim any expertise—are welcome to correct my account, but I think it is accurate.
I was, perhaps, less inclined than most to take official truth at face value due to early experiences in what was to become my field. As an undergraduate at Harvard in the early sixties, I had a conversation with a fellow undergraduate who informed me—he had no idea who I was—that he could not take an economics course at Chicago because he would burst out laughing. Even aside from what I knew about the controversy between the Chicago and Harvard schools, it seemed to me that the fact that a student who had probably taken one introductory course in the field thought himself competent to judge, with confidence, which school was correct, was a good reason to be skeptical of the claims of his teachers. And, within a decade or two, the Harvard school had largely conceded that, on at least some of the debated points, they had been wrong.
In the case of global warming, I am inclined to accept the official version of the climate science, since I don't know enough about the subject to be competent to question it. But the official version of the associated economics, the claim that the rate of warming implied by the climate science will have large negative effects, strikes me as unconvincing and probably wrong, for reasons I have discussed here in the past.
(Many more of my posts on the subject.)