Pure cholesterol versus oxidized cholesterol and the role of antioxidants.

Now this is interesting.  "Purified cholesterol at the same dose produced no effect."  This painstaking chemistry is rare and goes to show that you can call something cholesterol, but it may not actually be cholesterol.  All these oxygen adducts of cholesterol and other junk are very aggravating to the artery, causing "intimal, fibrous lesions without foam cells or hypercholesterolemia" the sort of thing you might see in advanced scorbutic lesions of the artery wall.  This probably pertains to cheap Vitamin C too, which might contain some harmful junk.  Pure Vitamin C of good quality, not questionable and impure, is probably as important.    

Arch Pathol Lab Med. 1976 Nov;100(11):565-72. Angiotoxicity and arteriosclerosis due to contaminants of USP-grade cholesterol. Imai H, Werthessen NT, Taylor CB, Lee KT. Abstract Impurities were concentrated from several lots of cholesterol by recrystallizing cholesterol from methanol solution, retaining the mother liquor, and evaporating the residuum to dryness under vacuum. This concentrate contained the products of spontaneous oxidation of cholesterol and other contaminants from the original source. The concentrate increased the frequency of dead aortic smooth muscle cells and induced focal intimal edema in the rabbit 24 hours after gavage at 250 mg/kg. New or old cholesterol was similarly angiotoxic, the old more so than the new. Cholesterol purified via dibromination induced an increase in aggregate debris in 24 hours at 250 mg/kg but no increase in degenerated cells. The concentrate administered at a total dose of 1 gm/kg/seven weeks induced intimal, fibrous lesions without foam cells or hypercholesterolemia. Purified cholesterol at the same dose produced no effect.

The problem with food is that unless you keep it under nitrogen and don't cook any of your food, invariably there will be some oxidized cholesterol products.  My arteries balk at the sight of this crud.  The good news is that unlike the experimental condition above and in other experiments adding oxidized cholesterol, there isn't a whole lot of it in what you eat unless you exclusively eat low quality fast food that is fried the hell out of in oil that recirculates and boils in the air for sometimes weeks at a time, which is like an oxidation factory.  Then you might worry some about oxidized cholesterol.

The good news is that there is an enzyme that can prevent LDL oxidation called paraoxonase.

Paraoxonase active site required for protection against LDL oxidation involves its free sulfhydryl group and is different from that required for its arylesterase/paraoxonase activities: selective action of human paraoxonase allozymes Q and R.

The reality is that cardiovascular disease is rampant in industrialized nations where there is plenty of fruits and vegetables available 365 days a year.  If apples and oranges were the cure for heart disease, there would be no heart disease in the US.  By logical deduction, it is not a lack of orange or apple, but something else.

Like a broken record, many scientists the world over have implicated that the human need for Vitamin C and other essential nutrients is much greater than what the RDA maintains, and unfortunately what food can deliver.  Unless we all start eating a whole bunch of acerola cherries all the time, for example, you would need to eat 30 oranges a day or drink the equivalent of fresh squeezed juice to get a modest 2.7 grams of ascorbate.  The whole point of the idea of vitamins was to cover what nutritious food, like oranges and apples could not provide, especially given that trees only fruit 3-5 months a year, leaving humans ravaged by scurvy during the non-fruiting season, therefore creating the situation "cyclical scurvy."  When Vitamin C containing fruits and vegetables are available in the growing season again, the atherosclerosis accelerates during this period, not reduces, in order to build a more scurvy resistant arterial wall.  You want to have a consistent optimal dose at all times.

Now that was a tangent, but not really, as serum antioxidants like Vitamin C have everything to do with preventing cholesterol oxidation and enhancing PON function.  The understated and amazing observation made in 1976 is that purified cholesterol, free of oxidation products and contaminants, is harmless to the artery wall.