Eggs and cholesterol
A recent study potentially teased out the mechanism by which eggs raise LDL-C and ApoB, and it is not the cholesterol.
It's the choline. Choline bitartrate supplementation without added cholesterol increased ApoB and LDL-C to the same extent as eggs when choline was matched. ApoB-100 (a marker of LDL particle number) and LDL-C (the cholesterol content of LDL particles) were the same in both groups! However, the egg group had higher HDL-C (the "good" cholesterol), and lower overall hepatic cholesterol synthesis. This means that the average person maintains steady-state cholesterol levels regardless of dietary intake, provided choline intake is held constant.
Now, does this mean that choline is to be feared? In my opinion, no.
In this literature review, we learn that choline (and betaine from vegetables, lol) supplementation increases serum cholesterol because it assists with hepatic triglyceride efflux (removing excess fat from the liver). The choline gets methylated by methionine, folate, B12, and glycine to produce phosphatidylethanolamine and phosphatidylcholine. Both are needed to synthesize VLDL particles and shuttle excess fat away from the liver and keep your liver healthy. In the same review, we learn that choline supplementation is absolutely KING at preventing fatty liver in both animal experiments and humans on TPN.
In my opinion, we really can't have it both ways here. We can't say the eggs are bad because they increase ApoB-100 and LDL-C and make us susceptible to heart disease, but then turn around and say that eggs are good because the increase in ApoB-100 and LDL-C is protecting us from fatty liver. One of these ideas has to be wrong, unless preventing fatty liver also causes heart disease. but I don't personally buy that because I see no evidence for it.
Personally, I eat at least two to four eggs daily, and shoot for a choline intake of 750-1200mg. In the literature, choline intakes this high are associated with lower homocysteine in those with my MTHFR polymorphism (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2855263/). I can surmise from this that my MTHFR polymorphism puts so much stress on my choline supply that in order to adequately protect myself from fatty liver, I must eat eggs and/or liver if my approach toward correcting this issue is going to be nutritional.
However, if someone had a mutation affecting their ABCG5/G8 sterol transporters that caused them to become hypercholesterolemic when they consumed dietary cholesterol, I would absolutely suggest that those people not eat eggs or liver at all. In fact I would probably recommend an approach closer to veganism or pescetarianism without shellfish. Nonetheless, their approach would have to be different. It's not all black and white. Everyone needs a personalized approach to nutrition, and we shouldn't vilify nutrients across the board because context matters a lot.