Because medical authorities have always approached the cholesterol hypothesis as a public health issue, rather than as a scientific one, we’re repeatedly reminded that it shouldn’t be questioned.
This seems to sum up both how the public health community and the medical community at-large approach health issues. Once a consensus has been reached the issue is moot, and questioning the conclusion is not a scientific responsibility but rather an ethical mistake. We might reasonably agree that smoking is deadly, and that second hand smoke is not good, but why should questioning the degree to which it is harmful be beyond the pale.
It seems reasonable that there would exist a gap in motivation between pure science and applied medical science. Medical research is - at least in theory - motivated by a desire to help people. Pure science, so called, is - again, in theory - motivated solely or primarily by a desire to uncover how the world works for the sake of discovery alone. Or at least that’s the grade school rap on science. But why should the scientific method be excised from issues of public health concern? Millions of Americans are on some kind of diet, exercise, and/or pharmaceutical regimen to control their cholesterol in the hope that this will stave off heart disease. And yet, as the linked NYTimes op-ed reports, the evidence is actually kind of wishy-washy, but nobody wants to question a medical consensus when the public health (!) is at stake.
This almost provides an opportunity to question where we draw the line between issues of personal and public health. But time begs this be left for another post.