Triglycerides divided by five

3. September 2008 William Davis (8)
Here's a bit of lipid tedium that might nonetheless help you one day decipher the meaning of shifts in your cholesterol panel.

Recall from prior discussions that conventional LDL cholesterol is a calculated value. Contrary to popular opinion, LDL is usually not measured, but calculated from the Friedewald equation:

LDL cholesterol = Total cholesterol - HDL cholesterol - triglycerides/5

For the sake of simplicity, let's call total cholesterol TC; HDL cholesterol HDL, and triglycerides TG.

We've also talked in past how a low HDL makes calculated LDL inaccurate, sometimes wildly so. (See Low HDL makes Dr. Friedewald a liar.)

Here's yet another source of inaccuracy of the Friedewald-calculated LDL: any increase in triglycerides.

Let's say, for instance, that starting lipid panel shows:

TC 170 mg/dl
LDL 100 mg/dl
HDL 50 mg/dl
TG 100 mg/dl


You're advised to follow a standard low-fat, whole grain-rich diet advocated by "official" agencies (the diet I bash as knuckleheaded). Another panel a few months later shows:

TC 230 mg/dl
LDL 140 mg/dl
HDL 50 mg/dl
TG 200 mg/dl


(Obviously, I've oversimplified the response for the sake of argument. HDL would likely go down, LDL would change more depending on body weight, small LDL tendencies, and other factors. You'd also likely get fat.)

Now your doctor declares that your LDL has gone up and you "need" a statin agent.

Nonsense, absolute nonsense.

What has really happened is that the increased dietary intake of wheat and other "healthy whole-grain foods" has caused triglycerides to skyrocket. LDL increases, in turn, by a factor of TG/5, or 40 mg/dl. Thus, LDL has been inflated by the triglyceride-raising effect of whole grains.

This is yet another reason why the standard lipid panel, full of hazards and landmines, needs to be abandoned. But calculated LDL in particular is an exercise in frustration.

Though the example used is hypothetical, I've witnessed this effect thousands of times. I've also seen many people placed on statin drugs unnecessarily, due to the appearance of a high LDL cholesterol that really represented increased TG/5, usually induced by an excessive carbohydrate intake, including those commonly misrepresented as healthy such as whole grains.
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Comments (8) -

  • Anonymous

    9/2/2008 9:44:00 PM |

    very interesting.  What recommendations would you have with someone with low HDL of 40, Triglycerides of only 37, and LDL of 90 most of which are small particles?

  • Paul Anderson

    9/3/2008 6:12:00 AM |

    Surely the rise in LDL attributed to the increase in triglycerides would only be 20, as the increase in triglycerides was only 100 (The other 100 already being counted first time around) or am I missing something here.

    I have read elesewhere that there may actually be a rise in triglcerides during a period of active weight loss, which can result in a temporary rise in cholesterol.  If this is the case this would also, on the Friedewald formula, show an apparnet rise in LDL, when in fact all that was happening was that the body was utilising stored fat for energy.

    Does anyone have any views on how long after weight loss before cholesterol levels settle down?

    Do you need to get to an optimal weight before the lipid panel is returned to a normal/optimal level, whatever that is?

    Dr Davis - do you still hold to the 60:60:60 target, and have you revised your view on saturated fat.

    As an aside, where do you stand on protein consumption?  and its effect on blood sugar and circulating insulin levels?

  • Anonymous

    9/3/2008 9:55:00 PM |

    generally you see a low hdl with high triglycerides.  what if the hdl is low,say 40, and the triglycerides are low, say 37, all measured by NMR which shows lots of small particles.  Isn't this just a genetic problem, and maybe diet cannot address?

  • parky

    9/4/2008 1:04:00 AM |

    The math here seems backwards compared to your statement.  If TC  and HDL stay constant (a big IF), and TG goes up, then calculated LDL goes down, not up like you state.

    LDL=TC-HDL-TG/5

    or LDL + HDL + TG/5= TC

    I suppose what really happens is like your example, where TC AND TG both go up and TC goes up more than TG/5, giving a net increase in calculated LDL.

    Anyway, thank you for a great blog, and a great website.  Its great to see someone who actually measures what works and what doesnt!

  • Anonymous

    9/4/2008 6:19:00 PM |

    Dr Davis,
    This is somewhat off your topic.
    In your experience, have you noticed any blunting of the effect of niacin on HDL by antoxidants?
    Also, have you seen PMID 17662090,
    17214603, and 16230278?
    Your thoughts?
    I greatly appreciate the diligent
    work you have put forth in heart
    disase prevention!

  • Lizzi

    9/6/2008 2:58:00 PM |

    I think another way to look at this phenonema is to look at someone's total non-HDL cholesterol as the indicator of risk, not just LDLC.  Total non-HDL cholesterol approximates measuring Apo B. BTW, Dr. Davis, I have thoroughly enjoyed your blogspot.

  • Alvin Wong

    11/4/2008 9:53:00 AM |

    Whatever the case maybe, I thought that our liver is intelligent enough to balance to production and recycling of the cholesterol particles; irrespective whether they are being carried by LDL or HDL.

    Wouldn't by this theory, the total cholesterol level is constant until ingestion of saturated fats and red meat or conversely reduction by exercise etc.

    http://www.4life-stay-healthy.com
    http://www.4life2u.com/r/alvinwong

  • buy jeans

    11/3/2010 2:39:57 PM |

    What has really happened is that the increased dietary intake of wheat and other "healthy whole-grain foods" has caused triglycerides to skyrocket. LDL increases, in turn, by a factor of TG/5, or 40 mg/dl. Thus, LDL has been inflated by the triglyceride-raising effect of whole grains.

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