I probably should never have entertained the Dr Davis derail. The whole bringing up of this character was your attempt to answer my question "What’s the evidence that [atherosclerosis] only takes place in individuals with arterial wall injury or without the ability to repair damage?"

Your response was "Some people live a long time with high(er) fat diets and no heart disease". But this is not evidence that atherosclerosis only takes place in individuals with arterial wall injury or without the ability to repair damage. That could equally be evidence that some people are genetically less predisposed to arterial retention, regardless of arterial wall injury, for example. There are plenty of hypotheses that negate your proposed one that are equally likely on the evidence you've provided. So this whole thread is just a tangent that doesn't engage with the core question. That said, here goes:

My point on CAC was that your entire argument hinges on being able to look at a CAC score and say "this score is a reliable indicator of whether a person has coronary artery disease". But if you're under 40 and actually have CAD, there's a 58% chance that when you get your test results back, it will show 0 CAC (even though you have CAD!). So demonstrably, CAC is a poor proxy for CAD, and so a lynchpin proposition in your argument is clearly false. Whether the numbers look different when read a different way is irrelevant. The above is true, and demonstrates how CAC is not a reliable metric.

> I don't think Dr Davis has said serum cholesterol is irrelevant, the statement I linked is that dietary fat removal doesn't stop CAC score increasing.

Literally from the article you linked: "Can you look at your cholesterol and say “Oh, my cholesterol is 240. I must have heart disease.”? No, of course not — cholesterol is virtually worthless when it comes to predicting heart disease"

So he says exactly that, unless you're willing to quibble over a semantic difference between "virtually worthless" and "irrelevant".

> Why we should believe him is that he's got a feedback loop with a measuring machine

It's not just "why should we believe him", it's "why should we believe him over meta-analyses of RCTs, and other high quality data?" Look at where "expert opinion" and "case reports" (which is the evidence you're citing, if we're being generous) sits relative to the MAs of RCTs that I'm bringing to the table on the hierarchy of evidence (https://en.wikipedia.org/wiki/Hierarchy_of_evidence). It's not clear to me why you're throwing out robust evidence with comparatively low risk of systematic bias and relying on bottom-tier evidence instead. Can you please explain to me why this is a superior epistemic framework?

> He's a quack selling a book?

Yes. I'd take a quack to be anyone wearing the coat of science while violating the standards of modern science. Whether or not he stands to gain (or cares about) the money his book makes isn't relevant to that claim, it's based entirely on the nature of what he has to say/publish.

Indeed, going back to the previous point, dismissing the enormous body of high quality evidence showing LDL cholesterol is a causal agent in atherosclerosis by referring to serum cholesterol measurement as "virtually worthless" merely because of his own personal experience, with the plethora of biases that entails, is textbook quackery. The fact that he's published a pop science book that blames many of the ills of the world on wheat with no evidence to back up such an assertion is just the cherry on top.

So I don't need to speculate why he's a quack, and his salary doesn't alter my point. Maybe he does it because being a number one bestseller satisfies his ego in a way nothing else can. Maybe having that accolade means he can charge more for his cardiology services, so there's an indirect financial benefit. Maybe he genuinely believes wheat is the devil's food? I don't really care, my point is that his output suggests he's not a sound practitioner of the scientific method.

Your entire argument here seems to boil down to "there's this guy who sees patients and he says they're not leaving his practice and they're getting better, how would he have patients if everything he says about heart disease wasn't true?" This is wild, the kind of arguments I see from homeopathy advocates. We should always aim for the evidence base most likely to be free from bias. That is not one clinician's account of how they do things.