The contemporary medical literature is replete with macro and other large studies that attempt to extrapolate a correlation between heart attack risk and blood lipids. The last two columns, “Understanding Your Lipid Panel” and “The Cause and Treatment of Heart Disease” address this issue from different directions. In this column we will attempt to put a fine point on the critical matter of lipid ratios.
In the 1960’s Total Cholesterol (TC) became a common and inexpensive test. As the principal metric of “the Lipid Hypothesis” popularized by Ancel Keys and then the American Heart Association, it became the universal marker for predicting heart disease risk. But that was more than half a century ago. We’ve come a long way since then.
The “treatment,” i. e. medical advice, then and now for high TC was to eat less saturated fat and other animal foods with high cholesterol content. This was the modality even though the body needs cholesterol for many essential purposes and makes up what we don’t eat by manufacturing it as needed. The threshold for TC was and remains today 200mg/dl.
Low density lipoprotein (LDL) is a component of TC. Even though the common test used to determine LDL was and is a calculated value, not a direct measurement, it became a popular target in the 80’s when big pharma developed drugs – statins – that lowered it. By lowering LDL, statins also lowered total cholesterol. So, doctors prescribed statins to anyone and everyone whose TC was over 200. Today, Lipitor, Crestor, Zocor, and its generic Simvastatin, account for $20 billion in world-wide annual sales.
In recent decades the other components of the Lipid Panel – High Density Lipoproteins (HDL) and Triglycerides (TG) – have taken on increased importance in understanding Cardio Vascular Disease (CVD) risk.Unfortunately, these developments have garnered little attention since the pharmaceutical industry has not yet developed blockbuster drugs to influence them. Fish oil lowers Triglycerides, but fish oil cannot be patented.
Most lipid panel lab results these days do however include a ratio of TC to HDL with a recommendation that it should be less than 5.0. In other words, if TC is 200, then HDL should not be less than 40. While this at least recognizes the importance of HDL, it is hardly a standard to be emulated. It is, in fact, borderline dangerous. Optimal is ≤3.5.
A somewhat higher standard coming into wider use is the inverse of this fraction, i.e. HDL/TC. However, the standard for this fraction is ≥0.24 = ideal. Translated, that is closer to a ratio of 4.0, versus 5.0 in the TC to HDL ratio cited above.
Many enlightened practitioners today, however, use the ratio of Triglycerides to HDL (TG/HDL) as “the single most powerful predictor of extensive coronary heart disease among all the lipid variables examined,” according to just one of many articles in the literature. The study I quote is in Clinics at PubMed Central 2008 August 63(4) 427-432. Note, by the way, that neither TC nor LDL is a factor in this formula. This ratio is considered by informed clinicians today as more reliable than LDL, or TC/HDL, or high sensitivity (hs) C-reactive protein (CRP), the marker my internist/cardiologist uses.
Using this new gold standard, a TG/HDL ≤ 1.0 is considered ideal, a ratio of ≤2.0 is good, a ratio of 4.0 is considered high and 6.0 much too high. My recent TG/HDL = 0.35, which is interpreted to mean a very low probability of heart attack.
As the patent on Lipitor is about to expire, and the other name-brand statin drug patent expirations are not too far behind, big pharma is hard at work looking for the next blockbuster drug to lower Triglycerides or raise HDL. Alas, so far, diet -- that is, our dietary intake (as in, “we are what we eat”) -- is the only thing that seems to work, and big pharma isn’t in that business.
Agribusiness, however, has seen the potential for a big piece of the action here. Unfortunately, there isn’t much profit in “real food.” Ask your local farmer. The increasingly popular processed foods -- the so-called “heart healthy” foods we are being encouraged to eat in large quantities -- do not improve the TG/HDL ratio. They make it worse!
In the coming weeks we will return to the subject of healthy eating. Subjects will include “Sugar: What do we mean?” “Fructose: Where and what is it?,” “Intermittent Fasting: Is it a good idea?,” “Ketosis and Autophagy,” and “Cooking with Oils: good and bad choices,” Our goal will be to help the reader improve their TG/HDL ratio. Of course, to do that, you will need to have a baseline Lipid Profile. If you haven’t had a Lipid Panel done, or don’t know yours, ask your doctor to do one. And ask him to see how yours shapes up using the new gold standard for CVD risk: the TG/HDL ratio.
© Dan Brown 10/9/11