I believe that we can all agree that the commonly obtained Friedewald LDL cholesterol (what I call "fictitious" LDL cholesterol) is wildly inaccurate. 100%--yes, 100% inaccuracy--is not at all uncommon.
This flagrant inaccuracy, unacceptable in virtually every other discipline (imagine your airplane flight to New York lands in Pittsburgh--close enough, isn't it?), is highlighted in the University of California study by Stanhope et al I discussed previously .
32 participants consumed either a diet enriched with either fructose or glucose. Compared to the effect of glucose, after 10 weeks fructose Increased LDL cholesterol (calculated) by 7.6%
Increased Apoprotein B (a measure of the number of LDL particles) by 24%
Increased small dense LDL by 41%
Increased oxidized LDL by 12.6%
In other words, conventional calculated LDL substantially underestimates the undesirable effects of fructose. The divergence between calculated LDL and small LDL is especially dramatic. (By the way, this same divergence applies to the studies suggesting that calculated LDL cholesterol is reduced by low fat diets--While calculated LDL may indeed be reduced, small LDL goes way up, a striking divergence.)
This is yet another reason to not rely on this "fictitious" LDL cholesterol value that, inaccuracies notwithstanding, serves as the foundation for a $27 billion per year industry.