Public Health

When we see the flip flopping of advice I think it tells us the science is inconclusive or the relationship noisy.

https://pubmed.ncbi.nlm.nih.gov/27292972/ Here is a systematic review from 2016 saying high LDL is protective vs low LDL, which goes against the current lipid hypothesis - I just point this out because it goes to your point that the advice given flip flops! - Update - I made a post just reviewing this paper here

This was a good video, but the core question is does LDL CAUSE atherosclerosis or is it associated with atherosclerosis? The video above even says the body will make LDL regardless of diet, so its clearly biologically necessary (that is to say LDL is not a disease). Bad Cholesterol is a poor name for LDL since it is biologically necessary.

There is literature currently saying decreasing LDL has a very small, but real risk reduction across a large population. But since its such a weak signal, I think LDL is a correlated biomarker and not the cause of atherosclerosis. i.e. If every fire you see has firefighters, you might start to think that firefighters start fires.

In the literature there are much stronger hazards to cardiovascular outcomes then LDL, such as metabolic dysfunction, diabetes, hypertension, etc. And very importantly differentiating healthy LDL that gets reused, vs damaged (glycated, oxidized) LDL

LDL is a risk factor, but it should be one datapoint in a panel (obesity, insulin sensitivity, hyper tension, CAC scores!!!, previous CVD events), not just a biomarker people try to treat in isolation.

If this is of interest, I recommend reading this writeup on LDL, its very balanced and cites its sources with confidence scores (the little numbers) https://www.dietdoctor.com/cholesterol/elevated-ldl-cholesterol