Carbohydrates and LDL

There's a curious and powerful relationship between carbohydrates and LDL particles. Understanding this relationship is crucial to gaining control over heart disease risk.

(Note that I did not say "LDL cholesterol"--This is what confuses people, the notion that cholesterol is used as a surrogate marker to quantify various lipoproteins, including low-density lipoproteins, LDL. I'm NOT interested in the cholesterol; I'm interested in the behavior of the low-density lipoprotein particle. There's a difference.)


1) Increase triglycerides and very low-density lipoprotein particles (VLDL)
2) Triglyceride-rich VLDL interact with LDL particles, making them smaller. (A process mediated by several enzymes, such as cholesteryl-ester transfer protein.)
3) Smaller LDL particles are more oxidizable--Oxidized LDL particles are the sort that are taken up by inflammatory white blood cells residing in the artery wall and atherosclerotic plaque.
4) Smaller LDL particles are more glycatable--Glycation of LDL is an important phenomenon that makes the LDL particle more atherogenic (plaque-causing). Glycated LDLs are not recognized by the LDL receptor, causing them to persist in the bloodstream longer than non-glcyated LDL. Glycated LDL is therefore taken up by inflammatory white blood cells in plaque.

Of course, carbohydrates also make you fat, further fueling the fire of this sequence.

The key is to break this chain: Cut out the carbohydrates. Cut carbohydrates and VLDL and triglycerides drop (dramatically), VLDL are unavailable to transform large LDL into small LDL, small LDL is no longer available to become oxidized and glycated, blood sugar is reduced to allow less glycation. Voila: Less atherosclerotic plaque growth.

Yet the USDA, American Heart Association, and the Surgeon General's office all advise you to eat more carbohydrates. The American Diabetes Association tells you to eat 70 grams or so carbohydrates per meal. (Yes: Diabetes, the condition that is MOST susceptible to these carbohydrate effects.) Follow their advice and you gain weight; triglycerides and VLDL go up; calculated (Friedewald) LDL may or may not go up, but true measured LDL (NMR LDL particle number or apoprotein B) goes way up; small LDL is triggered . . . You know the rest.

The dance between carbohydrates and LDL particles requires the participation of both. Allow one partner to drop out of the dance and LDL particles will sit this dance out.

Comments (16) -

  • Jon

    4/4/2010 5:12:14 PM |

    What kind of carbs are we talking about exactly though? Is there a difference between carbs in fruits and vegetables vs breads? And what should I replace them with?
    (not looking for an argument, I would  just like to know).


  • Peter

    4/5/2010 12:49:40 AM |

    I wonder what the rationale is for the Diabetes Association's recommendation to eat a lot of carbs.
    Right or wrong, there must be some logic to it.

  • Drake

    4/5/2010 1:57:51 AM |


    I think you'll find this site and TYP focuses on cutting out the carbs most responsible for inflammation.  This includes getting rid of wheat and sugars.  Read this site for an evening or two and you'll quickly find out what to avoid.  The topics on the left column contain a wealth of information.

    I cut out all grains and sugars and limit my fruits to mostly berries (too much sugar in most everything else).  I eat meat, lots of vegetables, nuts, seeds, eggs, and some berries.  You'll get all that your body needs from those sources.  Ditch the bread; you don't need it.

  • Anonymous

    4/5/2010 1:07:09 PM |

    Dr. Davis,

    My older brother was recently diagnosed with Type II diabetes. I sent him many of your links but he tells me the classes he goes to, put on by the doctor, tell him he can eat 75 cabs per meal as you talk about in your recent post.

    The cabs include bread, oatmeal, and even chocolate. Any advice on how else I can get it through his thick skull he should not be eating this junk? I love him and want him around for many years.

    Thank you.

  • nightrite

    4/5/2010 3:56:14 PM |

    The paleo people will tell you to drop the carbs and replace those calories with more fat, especially saturated fat.

    Of all the carbs breads/grains are the worst and then fruits so keep those to a minimum if not total elimination (small amounts of berries are ok).

  • Christine

    4/5/2010 5:05:42 PM |

    I was just signing in to address the same question as Jon. Actually to put in my 2-cents worth:  When you say drop all carbohydrates, surely you mean all high glycemic carbs - the high starch carbs like wheat and other grains (breads, cereals, even gluten-free grains), potatoes, white rice, plus moderate those carbs that are very high in sugars like carrots, onions, corn, the list goes on.  I find it confusing, and other readers may also, for you to say cut out all carbs. For if that is the case, what do we eat?
    I've been reading your blog for some time and find it to be most helpful, but this is the one area in which I wish you would be more specific.
    Thanks for being there. The world needs you.

  • mojodiver

    4/5/2010 5:31:50 PM |

    Same here. I had great success in my cholesterol numbers and weight as a result of lowering my carb intake to ~70g per day. I don't eat grains and prefer to get my carbs via colorful fruits and veggies.

    I exercise a lot now too.

    When you mean cutting carbs, what kind and to how much are you recommending?

  • StephenB

    4/5/2010 6:18:20 PM |

    Thanks for the post. I did not know the mechanism for small LDL being formed or for their getting into arteries before reading this entry.

  • W8liftinmom

    4/5/2010 8:05:42 PM |

    IMO, common sense would dictate keeping the better more nutrient dense carbs and limiting the less nutrient dense and starchy carbs.  So stick to mainly vegetables as your carb source - that's how I like to do it.

  • Dr. William Davis

    4/5/2010 10:10:35 PM |

    Hi, Jon--

    Vegetables are, of course, desirable foods. Some fruit.

    Beyond this, the sensitivity to carbohydrates is best judged individually with at least a HbA1c or, even better, a one-hour postprandial glucose.

  • Dr. William Davis

    4/5/2010 10:11:21 PM |


    The most persuasive tool is to get your brother to check occasional 1-hour postprandial glucoses.

    These high values can be downright hair-raising.

  • Dr. William Davis

    4/5/2010 10:12:22 PM |

    By the way, I will start a series of Heart Scan Blog posts called "What to eat" to clarity the confusion.

    This is also already posted in exhaustive detail in Special Reports on the Track Your Plaque website.

  • Anonymous

    4/7/2010 6:54:03 PM |

    I'd like to know where lentils, chickpeas and beans sit.
    When I've tested I get very little BG spike after eating them

  • Ned Kock

    4/8/2010 3:40:51 PM |

    Indeed, very good advice Dr. Davis.

    It is worth noting that low fasting triglycerides, especially below 70 mg/dl, are a marker for large-buoyant LDL particles:

  • Peter

    4/8/2010 4:57:00 PM |

    Dr. Davis, How can we tell which of these is the main problem?

    1.  Wheat.  The cultures that eat rice or corn and beans don't seem to have much heart disease or diabetes.

    2. Refined carbohydrates.  The cultures that don't have many of the diseases of civilization don't have Cheerios, etc.

    3. Carbs in general.  All carbs seem to raise our post-prandial
    glucose levels.

    4. Sugar and it's variants.  Increasingly sugar seems to be linked with health problems.

  • Anonymous

    4/9/2010 8:51:07 PM |

    Hi Ned Kock
    I have read your article, and I'd like to know how much exercise is considered excessive.