To track small LDL, track blood sugar

Here's a trick I learned after years of fussing over people's small LDL.

To gain better control over small LDL, follow blood sugars (blood glucose).

When you think about it, all the foods that trigger increases in blood sugar also trigger small LDL. Carbohydrates, in general, are the most potent triggers of small LDL. The most offensive among the carbohydrates: foods made with wheat. After wheat, there's foods made with cornstarch, sucrose (table sugar), and the broad categories of "other" carbohydrates, such as oats, barley, quinoa, sorghum, bulghur, etc.

Assessing small LDL requires a full lipoprotein assessment in which small LDL particles are measured (NMR, VAP, GGE). Not the easiest thing to do in the comfort of your kitchen.

However, you can easily and now cheaply check your blood sugar. Because blood sugar parallels small LDL, checking blood sugar can provide insight into how you respond to various foods and know whether glucose/small LDL have been triggered.

Here's how I suggest patients to do it:

1) Purchase an inexpensive blood glucose monitor at a discounter like Walmart or Walgreen's. You can buy them now for about $10. They're even sometimes free with promotional offers. You will also need to purchase lancets and test strips.

2) With a meal in question, check a blood sugar just prior to the meal, then again 60 minutes after finishing the meal. Say, for example, your pre-meal blood sugar is 102 mg/dl. You eat your meal, check it 60 minutes after finishing. Ideally, the postprandial (after-meal) blood sugar is no more than 102 mg/dl, i.e., no higher than pre-meal.

Perhaps you're skeptical that oatmeal in skim milk with walnuts and raisins will do any damage. So you perform this routine with your breakfast. Blood sugar beforehand: 100 mg/dl. Blood sugar 1 hour post: 163 mg/dl--Uh oh, not good for you. And small LDL will be triggered.

This approach is not perfect. It will not, for example, identify "stealth" triggers of blood sugar and small LDL like pasta, for the same reasons that pasta has a misleadingly low glycemic index: sugars are released slowly and not fully evident with the one-hour blood sugar.

Nonetheless, for most foods and meals, tracking your one-hour postprandial blood sugar can provide important insight into your individual susceptibility to sugar and small LDL-triggering effects.

Comments (28) -

  • Anonymous

    12/23/2009 8:05:52 PM |

    Would glycated hemoglobin also be an accurate way to track small LDL? Just thinking it may be easier to get that tested, which should give a decent account of sugar intake for the past several months, than measure glucose daily. Although I'm not sure if it correlates to small LDL as well.

    But if so, what is an optimal glycated hemoglobin for non-diabetic types?

  • TeDWooD

    12/23/2009 10:59:14 PM |

    I liked what you put about the blood sugar being released slowly in meals like pasta. When you take you blood pressure test you should be very relaxed as well.
    I have wrote about blood pressure highs and lows in my blog, and what foods are recommended. You can find it here:

  • Jim Purdy

    12/24/2009 1:26:58 AM |

    I have another tracking device which I like much better than my blood glucose meter

    A finger-tip pulse oximeter!

    I sometimes tend to have tachycardia and very unpleasant chest pains, and I have often used my finger-tip pulse oximeter to see what's going on.

    Until a few months ago, I would often have chest pains, emergency room visits, and one 9-1-1 ambulance call because I thought I was having heart attacks.

    All those ER visits got expensive, especially when the hospitals insisted on keeping me for 2-3 days each time to run zillions of dollars of tests.

    Often those attacks followed a greasy meal with something like bacon double cheeseburgers, and I "knew" that the fat was the culprit.

    However, after several low-carb bloggers directed my attention to the buns instead of the meat, I used my pulse oximeter to identify the problem foods.

    Yes, indeed, it was carbs, especially things like bread and -- much to my surprise -- ordinary breakfast cereals. I still miss my sandwiches and my Corn Chex, but I don't miss all those emergency room visits.

    I love my finger-tip pulse oximeter!

  • DrStrange

    12/24/2009 2:05:57 AM |

    Important to note that blood sugar monitors for home use are VERY approximate and are only accurate by plus/minus 20%.  Also, may vary widely between two readings taken seconds apart. I usually take 3 readings, bang bang bang, toss out any far outlier and average the what's left.  Still approximate but it makes me feel like it is more accurate ;)

  • Anonymous

    12/24/2009 2:20:43 AM |

    Wow, and this is news:

    -just in

    Another 'bad' cholesterol linked to heart disease found

  • Anne

    12/24/2009 8:15:49 AM |

    Dear Dr Davis,

    You have been writing about Lp(a) for years....why is it that the so called 'mainstream' medical profession appears only to have discovered it very recently ? Here in today's BBC news: 'Another 'bad' cholesterol linked to heart disease found':

    Happy Christmas !

  • vin

    12/24/2009 9:54:25 AM |

    Dr. Davis.
    If I am not mistaken I remember you saying that oats contributed to forming large LDL particles and not the small LDL.

    I am unable to find the article. Maybe you can reproduce that article.

  • Kurt

    12/24/2009 1:05:14 PM |

    I did this per your previous suggestion. I took one-hour and two-hour postprandial readings. My blood sugar never rose above 122, and was back down near fasting level after two hours. My diet contains a moderate amount of whole grains but almost no sugar and no refined grains.

    You could clearly see the difference between a meal of, say, salmon and vegetables, which barely raised my blood sugar above fasting, and one of chicken and brown rice, which would raise it to 110 - 120. It was a useful tool for assessing my diet.

  • Chloe

    12/24/2009 7:02:48 PM |

    Good information.  I have no health insurance and make too much money to qualify for public assistance, yet do not make enough to pay for many (close to all) tests.  I do participate in GrassRootsHealth for vitamin D (level from 7 to now 94), so I use anything at home I can to monitor what I can.

    The ReliOn Micro glucometer from Wal-Mart is a great little meter. It runs $12 for the kit which includes a few lancets and a lancing device.  The strips are the "sippy" kind and require the smallest sample on the market, just a dot of blood, and they are the least expensive strips on the market at $21.75 for 50 count.  I use them occasionally to track my own BG levels.

    Reason I purchased the meter?  The story is familiar:  Too many grain carbs recommended as the "good diet" which led to obesity and then diabetes.  That was my story, too, but the meter was purchased for my cat, Kipper.  The vets are in on this BS too.  All that expensive Eukanuba, Science Diet, vet prescribed grain diet and now my baby is a diabetic.  I regret listening to that for years.  

    I prick his ear twice a day, give him 1U of Levemir insulin, and then I check myself, occasionally.  Grains very, very bad.  Protein and fat very, very good.  Kipper's and my blood glucose levels are normal now, but he still needs insulin.  I am currently diet controlled.  Glad to know my diet control yields heart-healthy effects, too.

    Recently I had a yen for cherry tomatoes and overindulged.  We are talking about a cup more than usual.  Checked by meter this produced a 15 point increase over normal.  

    That cheap but reliable meter from Wal-Mart, if used (sometimes we turn off the internal prompt to check because we do not want to check) is a great tool and for me now a multipurpose tool.

  • Anonymous

    12/24/2009 7:29:10 PM |

    I'm concerned regarding this statement:

    "And the broad categories of "other" carbohydrates, such as oats, barley, quinoa, sorghum, bulghur, etc."

    In your Cheerios post

    you have actually touted oats by showing a study that pit it against wheat and it was shown to actually reduce LDL; this makes sense considering oats are a source of soluble fiber.

    "High-fiber oat cereal compared with wheat cereal consumption favorably alters LDL-cholesterol subclass and particle numbers in middle-aged and older men"

    Heres also a study that showed improved blood glucose response at breakfast that followed an evening in which barley was consumed:

  • Anonymous

    12/24/2009 9:28:39 PM |

    Noting that your readership is growing internationally, it might be useful for people to understand that the units of blood test measurement that are used quite frequently here in this blog are different in the US from most other places worldwide. These conversion factors may prove useful:

    Cholesterol (total,LDL,HDL): 38.7 (eg HDL of 60 mg/dl (US) is 1.55 mmol/L elsewhere)
    Triglycerides: 88.6 (eg reading of 60 mg/dl (US) is 0.68 mmol/L elsewhere)
    Blood Sugar: 18 (eg FBS of 90 mg/dl (US) is 5 mmol/L elsewhere)

  • Dr. William Davis

    12/24/2009 11:36:27 PM |


    The drawback of HbA1c is that the feedback is not immediate. You cannot use it to gain feedback on a particular food or behavior.

  • Dr. William Davis

    12/24/2009 11:38:04 PM |


    I, too, learned this lesson with my pets. I have two Boston terriers who gained weight little by little on the cornstarch-first ingredient dog food I was feeding them. Now, choosing dog foods that are principally meat has finally allowed them to control their weight.

    I'm impressed with your cat's blood sugar checking!

  • Dr. William Davis

    12/24/2009 11:38:29 PM |

    Thanks for the conversion factors, Anon.

  • Vladimir

    12/25/2009 12:45:33 AM |

    Dr. Davis, I'm wondering if it's the total blood sugar that correlates with LDL, or the rise in blood glucose.  So, for example, if one has a fasting level of 95 and rises to 120 after a meal, is that better/worse than starting at 75 and rising to 105 -- in terms of increase in LDL?

  • Anonymous

    12/25/2009 7:11:36 PM |

    Jim Purdy,
    Can you give some details on how you use your fingertip pulse oximeter to identify problem foods?  What kind of readings do you see and when?  How do the readings correlate with high or low blood sugar?


  • Peter

    12/26/2009 1:58:05 PM |

       A friend of mine started giving his diabetic cat low carb catfood and the cat, now fine, went into insulin shock because her blood sugar had returned to normal unbenounced to my friend. Now, she is fine on no more insulin shots.

  • Jim Purdy

    12/26/2009 3:19:53 PM |

    Anonymous asked me:
    "Jim Purdy, Can you give some details on how you use your fingertip pulse oximeter to identify problem foods? What kind of readings do you see and when? How do the readings correlate with high or low blood sugar?"

    Sorry, I wasn't very clear. I use my pulse oximeter to track my pulse rate, which could also be done by a much cheaper blood pressure monitor. I use my pulse oximeter because I have it, and it is conveniently small.

    My pulse readings do correlate very well with my glucose meter readings for carbs, but  I don't really use it to directly track blood glucose, even though I have Type 2 diabetes. My most bothersome health symptoms are tachycardia and chest pain, and my pulse oximeter has helped me identify the problem foods, which are carbs and caffeine.

    As I said, my pulse readings correlate very well with my glucose meter responses for carbs, but my pulse oximeter also has the advantage of showing the effect of caffeine, which doesn't show up with my glucose meter.

    Also, my pulse oximeter shows my body's response almost immediately, whereas my glucose mete may take an hour or more.

    Thus, for me, with my concerns about tachycardia and chest pains, my pulse oximeter is much more useful than my glucose meter.

    Lest you think I got off topic, let me repeat that my pulse readings correlate closely with glucose readings, but much quicker.

    And again, a blood pressure monitor would give the same pulse information more cheaply.

    All this may apply only to me, or to diabetics who also have tachycardia. Everybody is different.

  • Anonymous

    12/26/2009 8:07:42 PM |

    Easily I assent to but I contemplate the brief should secure more info then it has.

  • Chloe

    12/27/2009 12:17:02 AM |

    Peter--Kip is on low carb, wet cat food once he was diagnosed in April (his 14th birthday!).  The vet wanted him on a prescribed mid-level carbohydrate food and an unbelievable amount of Vetsulin.  After finding, I started testing him, switched his food, and switched his insulin.  His BG levels run 40 to 120 (sometimes higher when he has a flare of pancreatitis) on 1U twice a day.  I have learned to keep shooting even when he runs normal sugars.  Congratulations to your friend for getting diet control.  I have been at this about 8 months with him and I am not sure he is going to go without insulin.  Still I am hopeful.  He has helped me on my diet though.  I can't cheat (really cheating myself) on mine anymore because I feel guilty about him AND since he often helps himself to my food I do not have anything he can't.  The household is strictly low carbohydrate: Meat, fat, and green vegetables. Glad to hear a good story about a cat becoming diet controlled. Human and feline we are all healthier these days.

  • Grandma S.

    12/27/2009 2:38:22 AM |

    Dr. Davis-How does the blood sugar rise correlate with taking Niacin and LDLs?  It raises my blood glucose levels, raises my HDL, and lowers my Trigl.  Thank you!

  • Anonymous

    12/27/2009 4:25:26 AM |

    Thanks Jim Purdy.  Just to clarify, exactly what are you seeing on your pulse oximeter when a food is "bad?"  For example, what is a good pulse reading and what is it when it is bad?  Do you track how long it takes to return to baseline?

    It is very interesting that it correlates with your glucose levels.  Are glucose levels high when your pulse is high and vice versa?  Even though the device is more expensive than a glucose monitor, you don't have the ongoing expense of the strips and of course don't have to stab yourself!  Of course a pulse oximeter wouldn't provide enough information for someone needing to treat diabetes but for those just curious about the effect of foods, it might suffice.

  • karl

    12/27/2009 4:42:40 AM |

    The question become is the small LDL the base risk factor or is it blood sugar (fructose?) .

  • Anonymous

    12/29/2009 3:53:23 PM |

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  • Anonymous

    1/8/2010 8:54:05 PM |

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  • Anonymous

    1/17/2010 7:28:51 PM |

    I would also like further information about oats, I remember other posts in this blog that show oats as beneficial for reducing small LDL

  • Anonymous

    1/29/2010 7:33:32 AM |

    "Because blood sugar parallels small LDL, checking blood sugar can provide insight into how you respond to various foods and know whether glucose/small LDL have been triggered."

    I am very interested in pursuing this, but do you have a cite for this? I googled up small LDL particle size and didn't see anything about blood sugar being a good proxy for that, although I'm sure I missed seeing a lot.

    Also, I'm interested in more information on the effect of oats. I, too, have been under the impression that it is a healthy choice.

  • buy jeans

    11/3/2010 10:24:34 PM |

    However, you can easily and now cheaply check your blood sugar. Because blood sugar parallels small LDL, checking blood sugar can provide insight into how you respond to various foods and know whether glucose/small LDL have been triggered.