The LDL-Fructose Disconnect

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.

Comments (8) -

  • Peter

    2/26/2010 5:29:27 PM |

    I keep hoping nutritional advice will get simpler, but it seems like to know what to have for dinner we need a lot of blood tests and a very savvy doctor to interpret them.

  • sdkidsbooks

    2/26/2010 7:51:04 PM |

    Dr. D,

    Get the ldl-fructose connection but still confused about the small particle ldl/Lp(a) and eating fats.  Is it beneficial or not to include "good" fats like olive oil, coconut oil,butter, grass-fed meats, etc. when you have a the small ldl/Lp(a)pattern?  Being a woman and not the skinny male, I do think my pattern is genetic and I'm doing all of your recommendations for diet/supplements and want to be sure I am not making things worse by including fats in my diet.



  • shel

    2/27/2010 12:00:23 AM |



    regarding fructose, maybe eating fruit instead of sugary junk for dessert and whatnot is the way to go. i can't bring myself to believe that, in the context of a truly simple whole-food diet, an amount of fruit each day is going to contribute to future ills.

    ~Dr Davis, i wonder if someone who eats a simple paleo diet free of sweetner, added fats and oils, dairy, legumes and grass seeds, and eats plenty of fruit, fatty grass fed meat, fish, greens, and some tubers has an increased risk of s-ldl compared to an average nutritionally ignorant patient who eats a typical SAD and is now trying to "clean it up" a bit.

    just musing aloud.

  • Dr. William Davis

    2/27/2010 2:35:53 AM |

    Jan and Shel--

    Yes, fats are good. We've just got to be selective in our fats.

    My recent comments about "genetic small LDL" were not meant to scare everyone off of fat, but just to make the simple point that there is a subset of people with small LDL whose pattern responds somewhat differently than most other people.

  • shel

    2/27/2010 4:01:09 AM |

    ...sorry. i meant to say "...has a 'lowered' risk of s-ldl compared to..."

  • Rick

    2/27/2010 4:54:42 AM |

    I notice that you don't include actual measured TOTAL LDL cholesterol. If this is substantially different from the calculated total LDL cholesterol, then your point about the inaccuracy of the Friedewald calculation is proven. As it is, it seems to me that you've merely shown that it may not be very useful (because size, density, and degree of oxidation may be more important), rather than actually inaccurate.

  • L

    2/27/2010 11:56:05 AM |

    the stanhope study is only useful for those who are already fat and getting fatter and considering supplementing their already excessive intake with fructose sweetened beverages.

    self experiment 2 months ago lasting 5 weeks: as much fruit as i wanted and more (i wanted to make sure i got at least my normal intake of approx. 2300 cals) and whey protein to get about 100 g protein/day. my calorie intake per day came to averarge approx. 2700 cals. maybe if i account for fiber the actual calories would be closer to normal.  with that amount of fruit i was consuming i was constantly full (uncomfortbably so at times). i was basically force feeding. i didn't gain weight, i still have six pack so there was no undesirable body recompostion. pure fructose consumption may have no associated feedback mechanism  and induce hunger as stanhope study states, but we can't say fruit does the same thing. i think the addition of fruit to diet maybe helpful to those with weight issues as it could displace more calorie dense stuff sweetened with sugar and has added fat(eg doughnuts, cookies). did i screw up my lipids? don't know.  may be when a study comes along that induces bad things using only fruit as the fructose source i'll know. my point: may be we shouldn't worry about SOME fruit in the diet. may be if i continued experiment longer i would get fat. i'll never know because the diet was unsustainable. turds were monstrous, but passable with more effort than i'm accustomed to or desire.

  • Neonomide

    3/4/2010 9:22:42 AM |

    Professor Lustig hates fructose yet claims that it`s toxic effetcs are blunted by fiber in fruits versus sweetened beverages. Obviously the speed of ingestion is somewhat critical in case of fructose.