The Short Version
No credible scientific evidence supports the existence of an "impenetrable" exclusion zone water barrier on arterial walls that blocks LDL or red blood cells. Peer-reviewed vascular biology research consistently demonstrates that LDL reaches and crosses the arterial endothelium via transcytosis and paracellular transport — processes central to atherosclerosis. While exclusion zone phenomena have been observed near hydrophilic surfaces in laboratory settings, the mechanism remains disputed, and no study has demonstrated such a barrier in living arteries.