Except you’re overlooking a key aspect of the glycocalyx.
Despite its clearly important role in general, the glycocalyx is not uniformly protective throughout the arterial tree, and, importantly, this is the case even under otherwise normal conditions.
As far as we know, at bifurcations and curvatures, especially of major arteries prone to plaque development, blood flow is disturbed and this on its own will still contribute to significant local thinning of the glycocalyx, even in the absence of other major metabolic risk factors. Certainly other factors like high blood pressure, smoking, diabetes, etc. can exacerbate this, but these regional differences can still occur without them. And evidence that certain things can support glycocalyx health in general doesnt prove that they can fully protect/restore it in these specific regions.
Here are some examples of what I’m talking about:
A 2006 study by Van den Berg et al. showed that mice fed a normal diet had an approximately 82% thinner glycocalyx at the carotid sinus compared with the common carotid artery, along with greater intimal thickening.
pubmed.ncbi.nlm.nih.gov/1615…
In a 2009 study, the same researchers also showed that impaired glycocalyx barrier properties at this location were associated with TWO- TO THREEFOLD GREATER LDL accumulation within the arterial intima.
pubmed.ncbi.nlm.nih.gov/1883…
So yes, there is little doubt that impaired glycocalyx barrier function can help increase LDL entry and accumulation, but the point is, even under otherwise healthy conditions, there can still be significant regional differences in glycocalyx structure and protection. But what we can control very effectively, though, is how much circulating LDL substrate is available to enter the arterial wall in the first place.
Also, I fully acknowledge these are animal studies, but the underlying relationship between disturbed blood flow, endothelial function, and atherosclerosis prone arterial regions is unlikely to be any different in humans.
The glycocalyx is obviously very important, but the key that arguments like yours don’t factor in is that its protective properties can vary A LOT depending on location, especially at the exact locations where we know atherosclerosis preferentially develops, and this can occur regardless of how healthy it may be elsewhere.
You cannot simply invoke the negative electrical charge of LDL and the glycocalyx to then conclude that LDL won’t enter the arterial wall if someone is metabolically healthy, or that metabolically healthy people with extremely elevated LDL have nothing to worry about, unless you provide evidence that specifically at branch points and curves of major arteries the glycocalyx maintains sufficiently effective barrier function to prevent clinically meaningful LDL entry and accumulation in metabolically healthy individuals.
As far as I know, there is no convincing evidence establishing that, which means you are potentially giving (many) people a false sense of security.