More on cholesterol – this time from Dr William Davis – the author of ‘Wheat Belly’. In this recent blog post Dr Davis considers the before and after cholesterol tests from a reader called Kate who has been on a wheat elimination diet. He looks at the relevance of triglycerides, HDL and LDL cholesterol and explains why the headline ‘total cholesterol’ figure is effectively meaningless and why cholesterol testing is completely misunderstood by many in the medical profession. This is from the Wheat Belly blog…
Here are Kate’s blood test results:
December of 2011 / December 2012
Total Cholesterol: 234 / Total Cholesterol: 210
Triglycerides 121 / Triglycerides 81
HDL 69 / HDL 85
LDL 141 / LDL 109
Here is Dr Davis’s interpretation:
Thanks for posting your numbers, Kate, and sharing you and your family’s experience. Let’s try and make sense of these values:
Kate’s triglyceride level dropped from 121 mg/dl to 81 mg/dl, a very nice reduction. This is due to the reduction in liver de novo lipogenesis, the conversion of the rapidly-digested carbohydrate of wheat, amylopectin A, into triglyceride-containing particles like very low-density lipoproteins, or VLDL.
Think of triglycerides in VLDL as the first domino: Once there are excess triglycerides as VLDL particles, they interact with other blood particles, especially LDL particles, in turn enriching LDL particles with triglycerides. This leads to a series of reactions in the bloodstream that cause the formation of small LDL particles. So Kate’s very nice reduction in triglycerides means that she is forming fewer small LDL particles. While conventional wisdom says that small LDL particles do not form until triglycerides are 150 mg/dl or greater, in real life this is absolute nonsense: It is true that a triglyceride level of 150 mg/dl is associated with flagrant excess of small LDL particles, but you can still have oodles of small LDL even with lower triglycerides. The contribution of triglycerides to forming small LDL particles essentially ceases when triglycerides are reduced to 60 mg/dl or less. (So keep on going, Kate: Aim for the ideal triglyceride value of 60 mg/dl or less by further slashing carbohydrates. Also, consider supplementing omega-3 fatty acids from fish oil, e.g., 1800 mg per day of EPA + DHA, the most effective way to reduce triglycerides after wheat/carbohydrate reduction.)
HDL is protective against heart disease, stroke, even cancer. In general, the higher the HDL, the better.
The excess de novo lipogenesis that yields excess VLDL particles characteristic of wheat consumption also affects HDL particles. HDL particles, like LDL, become enriched in triglycerides and become smaller, less protective, particles. Also, the excess triglycerides cause degradation of HDL, reducing the quantity persisting in the bloodstream. Thus, wheat-eating humans have lower HDL levels. As Kate’s experience demonstrates, lose the wheat and HDL goes up, often way up. (HDL cholesterols of 70, 80, 100 mg/dl are everyday events.) While she started with a favorable HDL, she now has a spectacular HDL level that is likely mostly of the beneficial large variety.
I call conventional LDL cholesterol fictitious LDL cholesterol. This is because this value is calculated–yes,calculated–from the Friedewald equation developed in the 1960s by Dr. William Friedewald:
LDL cholesterol = total cholesterol – HDL cholesterol – triglycerides/5
It is meant to estimate the quantity of cholesterol within the low-density fraction of lipoproteins in the bloodstream. Problem: The original Friedewald equation relied on several assumptions, including the assumption that the amount of triglycerides and cholesterol in ALL LDL particles was the same. In those of us following a wheat-free diet with limited exposure to junk carbohydrates, the triglyceride content of LDL particles is much lower, making the Friedewald equation invalid.
In a practical sense, it means that Kate’s Friedwald-calculated LDL cholesterol of 109 mg/dl likely overestimatesthe real LDL value. If Kate were to have her doctor draw, for instance, an NMR lipoprotein panel, she would see that her real LDL was something like 70 mg/dl (i.e., LDL particle number of 700 nmol/L, for those of you familiar with NMR lipoprotein panels). Or, if an apoprotein B were to be obtained, it would likely be something like 60-70 mg/dl–a very favorable value. So Kate does NOT have a high LDL cholesterol, just the misleading appearance of 109 mg/dl by the invalid calculation. Had an NMR LDL particle number or apoprotein B been obtained at both “before” and “after,” Kate would indeed have witnessed a drop in all these measures. While her fictitious LDL cholesterol also dropped, some people experience the opposite: an increase in fictitious LDL, but truly concealing a drop in the superior measures.
Total cholesterol is a useless, outdated value for a number of reasons.
First of all, total cholesterol is too crude a marker for anything. Yes, it is a crude statistical marker in a large population, but a useless predictor at the individual level. Total cholesterol should have gone the way of frontal lobotomies long ago.
Second, you can see by the Friedewald equation that, if the equation were solved for total cholesterol rather than LDL cholesterol, it would be become:
Total cholesterol = LDL cholesterol + HDL cholesterol + triglycerides/5
Note that a rise in HDL–something good–is unavoidably accompanied by a rise in total cholesterol–something presumed to be bad. In other words, total cholesterol would be misleading. Conversely, some stress that drops HDL, say, by 20 mg/dl would reduce total cholesterol by 20 mg/dl–once again, misleading. Total cholesterol is an absolutely useless value that has no business being measured or reported in modern healthcare.
Kate has done a wonderful job of transforming her lipid/cholesterol panel and reducing or eliminating her risk for cardiovascular disease–but not for the reasons often cited. The drop in triglycerides, the rise in HDL, and meaningless drop in fictitious LDL cholesterol that conceals a genuine reduction in LDL particles–it’s all good with wheat elimination . . . but it has nothing to do with cholesterol.
More, including Kate’s story, at: Cholesterol belly