The contemporary medical literature is replete with macro analyses and other epidemiological studies that attempt to show 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 Retrospective we’ll put a fine point on the subject of lipid ratios.
In the 1960’s Total Cholesterol (TC) became a common and inexpensive test. As the main metric of “the Lipid Hypothesis,” created by Ancel Keys and popularized by the American Heart Association, it became the universal marker for predicting heart disease risk. That was more than half a century ago. We’ve come a long way since then.
The dietary advice then and now for high Total Cholesterol was to eat less saturated fat and other animal foods high in dietary cholesterol. This was the modality even though the body needs cholesterol for many essential purposes (see Retrospective #24), and it makes up what we don’t eat by manufacturing it as needed. The threshold for high Total Cholesterol was established at 200mg/dl. It remains today at 200mg/dl.
Low density lipoprotein (LDL) is a component of TC. Even though the common test developed and used then and now 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. A recent AMA editorial suggested by 2020 Lipitor, Crestor, Zocor, and their generics will approach $1 trillion in world-wide annual sales.
At the same time medical science has come to have an increased understanding of other components of the Lipid Panel – High Density Lipoproteins (HDL) and Triglycerides (TG) –and their role in Cardio Vascular Disease (CVD) risk. Unfortunately, these developments have garnered little attention since Big Pharma hasn’t developed blockbuster drugs to influence them. Fish oil lowers Triglycerides (see Retrospective #22), but fish oil can’t be patented.
Most lipid panel lab results these days do however include a ratio of TC to HDL (TC/HDL) with a recommendation that it should be less than 5.0. So, if your TC is 200, then HDL should not be less than 40. While this at least recognizes the importance of HDL, it is not a standard to be emulated. It is dangerous. A good ratio is ≤3.5.
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, importantly, that neither TC nor LDL is a factor in this formula. This ratio is considered by informed clinicians today to be more reliable than LDL, TC/HDL, or chronic systemic inflammation, hsCRP, the marker my doctor 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, interpreted to mean a very low probability of heart attack.
Big Pharma is hard at work looking for the next blockbuster drug to lower Triglycerides or raise HDL. Alas, so far, diet -- that is, the food we eat -- is the only thing that seems to work, and Big Pharma isn’t in that business.
Agribusiness, however, sees the potential for a huge piece of the action here, but there isn’t much profit in “real food.” Ask your local farmer. But processed foods – that can be labelled and marketed as “heart healthy, have gained the stamp of approval of the American Heart Association, whose budget is largely supported by the very same Agribusinesses. These processed foods, however, do not improve your TG/HDL ratio. They make it worse!In the coming weeks we will return often to the subject of so-called “healthy eating.” Our goal will be to help YOU to improve your TG/HDL ratio. Of course, to do that, you will need to have a baseline Lipid Profile. If you haven’t had a Cholesterol Panel done lately, or you don’t know yours, ask your doctor to do one and send you a copy. And ask him to see how yours shapes up using the new gold standard for CVD risk: the TG/HDL ratio.