I have always been really puzzled by a dietary paradox. These are the undisputed findings that foods either high in cholesterol or highly cholesterogenic are associated with good health in old age especially with regard to cognitive decline.
I repeat these findings are not in dispute. Foods highest in cholesterol are exemplified by oily fish and seafood. It is difficult to find a voice dissenting from the health benefits of regularly eating these foods. Usually, despite there being no evidence to support it Omega-3 lipids are given the credit for the health plus.
Cholestero-genic foods, that is foods that have an ingredient that is readily and simply converted to cholesterol, are extra-virgin olive oil and fungi such as mushrooms of various types. The cholestero-genic ingredient in the former is squalene and in the latter, ergothionine.
Squalene is in highest concentrations in shark and ray oils so consumed mostly in the Japanese cultures. Squalene by the way is also the mysterious black-art ingredient of big-pharma’s vital vaccine adjuvants. Ergothionene is an antioxidant and so is given a ‘health plus’ press because of the assumption ( false at worst, unproven at best ) that anti-oxidants in the diet are good for you.
So why are these foods good for you? It is easy to explain why their cholesterol profile is not mentioned because anyone not branding the ‘c’ word as the devil is an apostate by definition. I think dietary intake of cholesterol has now been rehabilitated since it is known to have little/no effect of serum levels of cholesterol, however it is a struggle to find a magic ingredient to explain the foods’ benefits.
The more you obtain cholesterol via the diet the less is made by the liver and vice-versa The liver can synthesize all or very nearly all the cholesterol required by the body and set it in any form from low to high density lipoprotein droplets (VHDL, HDLl ‘good cholesterol’, LDL ‘bad cholesterol’).
Cholesterol is obviously and immediately essential or there would be no such fall-back mechanism. I did read long ago that lab-monitored cholesterol-free diets, as in totally free had a bad effect on the trialists, but this is just a memory now, I cannot find it. I also cannot find whether the liver can make 100% of requirements or not.
The liver’s cholesterol from scratch bio-synthetic pathway is quite complex and energetically expensive starting from a simple two carbon molecule joined to a coenzyme called acetyl-coA. This molecule is the principle feed-stock for mitochondrial energetics in the production of ATP as well as being the building block of fat.
The pathway is very important at the complicated end of the pathway nearer the final steps to cholesterol as it branches and twines into sterol based hormones or, at the very, end vitamin D which is made from cholesterol.
The ergothionines and squalenes are at the more complicated end and need little work to complete their sterol final destination.
IS requiring the liver to synthesize cholesterol a bad-thing? My guess is that it is.
Either the ‘good for you diets’ possess as yet unidentified ingredients that are ‘good’ or synergistic combinations common to animals, plants and fungi. Or, quite simply having to make your own cholesterol while possible is a bad thing.
Maybe the pathway being dedicated to cholesterol reduces energy available to mitochondria, maybe hormone production is unbalanced, maybe it damages the liver, maybe all sorts of things but I think this is where to look.
Cholesterol in the diet is good for you. Heresy for a while longer.
